BODYPUMP Research Report - Les Mills

BODYPUMP 

Research Report 

© 2007 Les Mills International Limited 1

Table Of Contents 

EXECUTIVE SUMMARY 

Les Mills International (2006) ………………………………………………………………………………………. 

THE AEROBIC DEMAND AND ENERGY EXPENDITURE DURING BODYPUMP 

Pfitzinger, P and Lythe, J 

UniSports Centre for Sport Performance, University of Auckland (1999) 

Introduction....................................................................................................................................................8 

Fat Weight Loss.............................................................................................................................................8 

Exercise Post-exercise Oxygen Consumption (EPOC) ................................................................................9 

Calculation of Caloric Expenditure Using Gas Analysis..............................................................................11 

METHODS...................................................................................................................................................12 

Subjects.......................................................................................................................................................12 

Procedures ..................................................................................................................................................12 

BODYPUMP ............................................................................................................................................13 

Cycling.........................................................................................................................................................13 

VO2 Max Test ..............................................................................................................................................13 

Results.........................................................................................................................................................13 

Discussion ...................................................................................................................................................17 

Aerobic Intensity ..........................................................................................................................................18 

Energy Expenditure .....................................................................................................................................19 

Additional Benefits of BODYPUMP .........................................................................................................20 

References ..................................................................................................................................................21 

AN ATTITUDINAL STUDY ON THE BODYPUMP WORKOUT 

AC Nielsen (1999) 

Objectives................................................................................................................................................... 23 

Methodology ................................................................................................................................................23 

Results.........................................................................................................................................................24 

Enjoyment of BODYPUMP ......................................................................................................................24 

Benefits of BODYPUMP ..........................................................................................................................24 

Injuries Resulting from BODYPUMP .......................................................................................................25 

Likelihood of Continuing BODYPUMP Class...........................................................................................25 

Comment on BODYPUMP.......................................................................................................................25 

Other Sporting Activities BODYPUMP Members Take Part In................................................................27 

Summary Discussion...................................................................................................................................28 


THE PHYSICAL AND PSYCHOLOGICAL RESPONSE TO 13 WEEKS OF STRUCTURED 

GROUP-FITNESS EXERCISE IN UN-TRAINED INDIVIDUALS: 

Lythe J, Pfitzinger P and Ho D 

UniSports Center for Sport Performance, University of Auckland (2000) 

Introduction..................................................................................................................................................29 

Methods.......................................................................................................................................................29 

Test Descriptions.........................................................................................................................................30 

Intervention..................................................................................................................................................31 

Data Analysis...............................................................................................................................................32 

Results.........................................................................................................................................................32 

Discussion ...................................................................................................................................................47 

Body Composition .......................................................................................................................................48 

Aerobic Fitness............................................................................................................................................49 

Upper Body Strength ...................................................................................................................................49 

Upper Body Muscular Endurance ...............................................................................................................50 

Lower Body Strength ...................................................................................................................................50 

Lower Body Muscular Endurance ...............................................................................................................50 

Psychological Well-Being ............................................................................................................................50 

Subject Adherence ......................................................................................................................................51 

Limitations....................................................................................................................................................51 

Conclusion...................................................................................................................................................51 

References ..................................................................................................................................................52 

Appendix......................................................................................................................................................53 

THE PHYSICAL AND PSYCHOLOGICAL RESPONSE TO 18 WEEKS OF STRUCTURED 

GROUP-FITNESS EXERCISE IN UN-TRAINED INDIVIDUALS 

Lythe J, Pfitzinger P & Ho D 

UniSports Center for Sport Performance, University of Auckland (2000) 

Introduction 

Methods 

Results 

Discussion 

Conclusions 

EXCESS POST-EXERCISE OXYGEN CONSUMPTION FOLLOWING BODYPUMP 

Lythe J 

UniSports Centre for Sport Performance, University of Auckland (2001) 

Introduction..................................................................................................................................................60 

EPOC...........................................................................................................................................................61 

BODYPUMP ............................................................................................................................................63 

Methods.......................................................................................................................................................64 

Subjects.......................................................................................................................................................64 

Body Composition .......................................................................................................................................64 

VO2 max.......................................................................................................................................................65 

EPOC Session.............................................................................................................................................67 

Results.........................................................................................................................................................67 

Discussion ...................................................................................................................................................70 


SUMMARY ..................................................................................................................................................71 

REFERENCES ............................................................................................................................................73 


EXECUTIVE SUMMARY 

LES MILLS INTERNATIONAL (2006) 

BODYPUMP is a high-repetition, resistance training, pre-choreographed exercise program 

choreographed and developed by the Les Mills BODYPUMP team. The potential benefits of 

BODYPUMP, including calorie and fat burning benefits, improved aerobic fitness, muscular strength 

gains, improved muscular endurance capabilities and positive psychological benefits, have been 

researched [1-5] by independent research teams contracted by Les Mills International over the period of 1999 

to 2001. The BODYPUMP team has utilized the information gained from this research to guide further 

development and improve the efficacy of the BODYPUMP program. 

To date the key research findings of the potential benefits gained from undertaking the BODYPUMP 

program are summarized as follows. All data reported can be viewed in detail within the main body of this 

report. 

Potential benefits of BODYPUMP supported by scientific research: 

• Calorie Burning Benefit: 

� An average of 483.1 (males) and 338.9 (females) calories can be burned during a 

BODYPUMP session. This equates to 8.4 (males) and 5.9 (females) calories per minute. The 

maximum number of calories burned has been shown to be 424 (female), and 603 (male) [1] . 

� An additional 10% of calories (32.3 kcal in males (n=5) experienced in performing 

BODYPUMP; 43.7 kcal in males (n=7) inexperienced in performing BODYPUMP) have 

been shown to be burned after the cessation of a BODYPUMP session, due to Excess Post- 

Exercise Oxygen Consumption (EPOC) [5] . 

• Fat Burning Benefit: 

� 88.6 (males) and 51.5 (females) calories of fat, and 394.4 (males) and 287.4 (females) calories 

of carbohydrate, have been consumed during a BODYPUMP session. This equates to 18.6% 

fat and 81.4% carbohydrate in males and 14.9% fat and 85.1% carbohydrate in females [1] . 

� Significant reductions in skinfold measures (23.7mm, males, n=16) and (33.8 mm, females, 

n=24) have been observed over a 13-week BODYPUMP training period where no other 

training activity or change in diet was undertaken [3] . 


� Significant reductions in percent body fat (2.9%, males, n=16) and (2.6%, females, n=24) have 

been observed over a 13-week BODYPUMP training period where no other training activity or 

change in diet was undertaken [3] . 

• Improved Aerobic Fitness: 

� During a BODYPUMP session the mean oxygen consumption has been shown to be 21.5 

ml/kg/min (males) and 19.0 ml/kg/min (females) with an average intensity of 41.6% VO2 max 

(males) and 39.8% VO2 max (females) observed. Males spent an average of 11.6 minutes and 

3.2 minutes, and females, 8.0 minutes and 0.6 minutes, above 50% VO2 max and 70% VO2 

max, respectively, during the same BODYPUMP session. The average heart rate during a 

BODYPUMP session has been shown to reach 138.2 beats per minute (males) and 132.6 

beats per minute (females). Males spend an average of 37.4 minutes, and females 40.2 minutes, 

above 70% of maximum heart rate during a BODYPUMP session [1] . 

� Significant improvements in ‘Beep test’ scores (change of 6.3, males, n=16; change of 4.3, 

females, n=24) measuring aerobic endurance, have been observed over a 13-week 

BODYPUMP training period where no other training activity was undertaken [3] . The ‘Beep test’ 

scores (n=11, males) further improved with an additional 5 weeks of BODYPUMP training [4] . 

• Muscular strength gains: 

� Increases in upper body strength (6.0 kg, males, n=16; 4.7kg, females, n=24) using the 6RM 

Bench Press as a measure, and lower body strength (9.4 kg, males, n=16; 20.0 kg, females, 

n=24) using the 6RM Leg Press as a measure, have been observed over a 13-week 

BODYPUMP training period where no other training activity or change in diet was undertaken 

[3] . These strength measures (n=11, males) continued to improve with an additional 5 weeks of 

BODYPUMP training [4] . 

• Improved muscular endurance capabilities: 

� Increases in upper body muscle endurance capabilities (4.3 kg, males, n=16; 5.5 kg, females, 

n=24) using the 70% 6RM Bench Press as a measure, and lower body muscle endurance 

capabilities (9.4 kg, males, n=16; 20.0 kg, females, n=24) using the 70% 6RM Leg Press as a 

measure, have been observed over a 13-week BODYPUMP training period where no other 

training activity or change in diet was undertaken [3] . 


• Positive psychological benefits: 

� High levels of enjoyment, an improved overall feeling of well-being, improvements in the 

performance of other sports and exercise activities, a feeling and sense of improved 

coordination, flexibility, muscle strength and tone have been reported (n = 200) [2] . 

� Positive changes in psychological scores have been observed in males (n=16) and females 

(n=24) following a 13-week BODYPUMP training period where no other training activity or 

change in diet was undertaken [3] . 

Future research: 

The Les Mills Research and Development team are currently reviewing all relevant past research. Further 

research is planned to extend and build on existing research findings in order to continue to improve and 

develop the BODYPUMP program. Future research will focus on strengthening the methodology and 

design of studies by addressing any limitations noted from past research (eg small sample sizes) as well as 

extending the number and depth of parameters examined (eg BODYPUMP exercise intensities in a large 

and diverse population, the acute and long term effects of BODYPUMP on hormonal changes, and the 

longitudinal effects of the BODYPUMP program on body composition such as lean muscle mass. 

References 

1. Pfitzinger, P. and Lythe, J. (1999). The aerobic demand and energy expenditure during 

BODYPUMP. Auckland, UniSports Centre for Sport Performance, University of Auckland. 

2. International Survey Company A.C. Nielson. (1999). An attitudinal study on the BODYPUMP 

workout. Auckland, International Survey Company A.C. Nielson. 

3. Lythe, J., Pfitzinger, P & Ho, D. (2000). The physical and psychological response to 13 weeks of 

structured group-fitness exercise in untrained individuals. UniSports Centre for Sport Performance, 

University of Auckland. 

4. Lythe, J., Pfitzinger, P & Ho, D. (2000). The physical and psychological response to 18 weeks of 

structured group-fitness exercise in untrained individuals. UniSports Centre for Sport Performance, 

University of Auckland. 

5. Lythe, J. (2001). Excess Post-Exercise Oxygen Consumption following BODYPUMP. UniSports 

Centre for Sport Performance, University of Auckland. 


THE AEROBIC DEMAND 

AND ENERGY EXPENDITURE 

DURING BODYPUMP 

Pfitzinger P and Lythe, J 

UniSports Center for Sports Performance, university of Auckland (1999) 

Introduction 

Several variables contribute to the effectiveness of an exercise training program in reducing body fat and 

improving the various components of fitness, including the frequency, intensity, duration and type of 

exercise. BODYPUMP is a high-repetition, resistance training, choreographed exercise program. 

Although the potential benefits of BODYPUMP have not been comprehensively quantified, the training 

program may elicit improved muscular endurance, increased aerobic fitness, fat weight loss, and 

maintenance of, or increases in, lean body mass. The objective of the present study was to measure the 

aerobic demand and caloric expenditure of a standard session of BODYPUMP. 

Fat Weight Loss 

The primary goal of any weight-loss program should be to lose fat weight rather than total body weight. To 

lose fat, an individual’s energy expenditure must exceed his or her energy intake. The variables that 

influence energy expenditure include resting metabolic rate (RMR), the thermic effect of food (TEF), and 

the thermic effect of physical activity (TEPA) [9] . Exercise increases total daily energy expenditure, leading to 

loss of fat mass. 

The body can be considered as consisting of two compartments: fat-free mass (FFM) and fat mass (FM). A 

minimal amount of fat is necessary to maintain hormone levels, metabolic processes and protect vital 

organs. Excess fat, however, is associated with a variety of lifestyle-related illnesses and has negative 

social connotations. Individuals should strive to lose body fat while maintaining lean body mass. Exercise 

increases energy expenditure and the loss of fat mass, while maintaining or increasing FFM. 

It takes 7,700 kcal (32,000 kJ) to burn 2.2 pounds (one kilogram) of fat. By increasing total daily 

expenditure, exercise can lead to a negative caloric energy balance. Low-intensity exercise as opposed to 

high-intensity exercise is prescribed by many practitioners as an effective way to lose fat mass because fat 

is the main fuel source for low-intensity exercise. Studies have shown however that although low-intensity 

exercise uses predominantly fat as a fuel source, the total amount of energy derived from fat may be 

greater during moderate to high-intensity exercise [14] . In addition, it is the balance between the total calories 

used and consumed, not the source of the calories used, that determines whether a person actually loses 


weight [14] . For example, as seen in Table 1, one hour of jogging utilizes both more total calories and more 

calories from fat than one hour of walking. 

Table 1: Caloric and substrate use during exercise bouts 

EXERCISE 

(mode) 

DISTANCE 

(miles) 

SPEED 

(mph) 

DURATION 

(mins) 

© 2007 Les Mills International Limited 9 

TOTAL CALORIES 

(kcal) 

CALORIES 

FROM FAT 

% kcal 

Walk 4 4 60 270 60 160 

Jog 4 6 40 450 40 180 

Jog 6 6 60 680 40 270 

Reproduced from Puhl and Clark (1992) 

Exercise influences total daily expenditure through the thermic effect of physical activity (TEPA). The effect 

of exercise on resting metabolic rate is still controversial. Exercise may increase resting metabolic rate but 

intensity, duration, frequency and subject variability impact the dynamics of RMR [10] . Some researchers 

suggest that there may be as much as an 8% increase in RMR following five weeks of exercise at 60% VO2 

max for 45 minutes, five days a week [11] , while others have suggested that exercise has little or no effect on 

RMR. 

Exercise Post-exercise Oxygen Consumption (EPOC) 

The two components comprising the thermic effect of physical activity (TEPA) are the energy expended 

during exercise and excess post-exercise oxygen consumption (EPOC). EPOC has been defined by 

Sedlock et al., (1989) as “the energy expenditure during the post-exercise period while the metabolic rate 

remains elevated above the pre-exercise level.” The energy expended during the activity itself accounts for 

the majority of exercise-related energy expenditure. EPOC, however, may have important implications for 

weight control, since it contributes to total daily energy expenditure. For example, if an individual has a net 

EPOC of 40 kcal per exercise session, and exercises four times per week for one year, his or her EPOC- 

related energy expenditure would total 8,320 kcal, representing over one kilogram of fat loss. EPOC occurs 

because of the time required to correct the disturbance in homeostasis caused by exercise [15] . Factors 

such as increased catecholamine concentrations [1] , and elevated core temperature requires time to return 

to pre-exercise levels. 

Both the intensity and the duration of exercise determine the magnitude of EPOC. Table 2 presents the 

results of a variety of studies investigating the magnitude of EPOC with various types, intensities, and 

durations of exercise. Although the magnitude of EPOC varied widely between these studies, they provide 

insight into the order of magnitude expected following an hour of exercise.

Table 2: Summary of EPOC studies 

STUDY n STUDY DESIGN 

Sedlock et 

[16] 

al., 1989 10 

Quinn et 

al., 1994 [15 ] 8 

Chad and 

Wenger, 

1995 [1] 

6 

Dawson et 

al., 1996 [2] 8 

Olds and 

Abernethy, 

1993 [12] 

7 

Cycling HS = 300 kcal 

@ 74% VO2 max 

LS = 300 kcal @ 51% 

VO2 max 

LL = 600 kcal @ 50% 

VO2 max 

Walking @ 70% VO2 

max for 20, 40 and 60 

minutes 

Cycling for 15 minutes 

@ 50% and 70% VO2 

max 

Cycling HI = 30 mins 

at 65% VO2 max 

MI = equal energy cost 

as HI @ 55% VO2 max 

LI = equal energy cost 

as HI @ 45% VO2 max 

60 minutes of 

resistance training 

(75% 1RM and 60% 

1RM) 


No. CALORIES from 

EPOC, % TOTAL 

HS = 29.4, 9.7% 

LS = 14.3, 4.7% 

LL = 12.1, 1.1% 

20 mins EPOC = 46.3, 

24.5% 

40 mins EPOC = 59.6, 

16.5% 

60 mins EPOC = 89.2, 

16.2% 

15 mins EPOC (50%) 

= 95, 50% 


= 190, 46% 


= 190, 51% 


= 95, 24% 

HI = 32.6, 6.3% 

MI = 27.8, 4.8% 

LI = 25.6, 4.6% 

EPOC ranged from 4 

to 135 kcal 

CONCLUSIONS 

Intensity of exercise 

(>50%) affects 

magnitude and duration 

of EPOC. Duration of 

exercise only affects 

duration of EPOC 

Exercise duration 

significantly affects 

EPOC 

Duration of exercise 

has a greater effect on 

EPOC than intensity 

The magnitude of 

EPOC was greater after 

high-intensity exercise 

compared to isocaloric 

moderate or low- 

intensity exercise 

Large inter-individual 

variation, no significant 

differences between the 

two resistance training 

protocols

Elliot et al., 

1992 [3] 9 

40 minutes of cycling, 

circuit training, and 

heavy-resistance lifting 


Circuit EPOC = 49±20, 

13.2% 

Cycling EPOC = 

32±16, 7.4% 

Heavy lifting = 51±31, 

20.6% 

Heavy-resistance 

training and circuit 

training result in an 

EPOC comparable to 

aerobic exercise 

HS = High speed; LS = Low speed; LL = Low level; LI = Low intensity; MI = Moderate intensity; 

HI = High intensity 

Calculation of Caloric Expenditure Using Gas Analysis 

Caloric expenditure during exercise can be calculated by measuring the volume of inspired or expired air 

and the concentrations of oxygen (O2) and carbon dioxide (CO2) in expired air. The respiratory exchange 

ratio (RER) is the ratio of the volume of CO2 produced to O2 consumed by the body per minute [5] . The 

respiratory exchange ration ranges from 0.70 if fat provides 100% of the energy utilized to 1.00 if 

carbohydrate provides 100% of energy for exercise [13] . During low intensity, mostly fat oxidation is 

occurring; therefore, the RER is in the lower end of the range. A subject that exercises at a higher intensity 

uses mostly CHO as energy, which is associated with a high RER value. It is generally assumed that 

protein contributes less than 10% of the energy utilized during exercise. Due to the modest contribution of 

protein to energy expenditure and the technical difficulty in measuring amino acid combustion, a non- 

protein respiratory exchange ratio is used to determine the energy equivalent. 

Lactate accumulates in the blood and muscles during high-intensity exercise. Lactate is subsequently 

either oxidized or converted to glycogen. If lactate returns to resting levels before the cessation of exercise, 

then gas analysis accurately reflects caloric expenditure because glucose is converted to lactate and 

eventually oxidized [4] . If lactate levels remain elevated upon the cessation of exercise, however, the 

measurement of caloric expenditure using gas analysis may underestimate the total energy expended. 

Studies have shown that the rate of fat oxidation is highest during moderate activity (approximately 65% 

VO2 max) [6] . There are several reasons why there is a shift from fat oxidation to CHO oxidation as exercise 

intensity increases, including the presence of intramuscular triglycerides, circulating catecholamines, lower 

adenosine triphosphate (ATP) production from fat per unit time, and the gradient of fatty acids between 

blood and muscle. As exercise intensity increases from low to moderate, it is likely that the total fat 

oxidation increases from because intramuscular triglycerides provide additional fatty acids [8] . During high- 

intensity exercise the rate of fat oxidation falls because of an increase in circulating catecholamines that 

stimulate glycogen breakdown and the rate of glycolysis, and suppress fat metabolism [6] . The shift from fat 

to CHO as exercise intensity increases is necessary for high-intensity exercise to occur because ATP is 

produced at a faster rate when CHO is metabolized compared to fat [6] . The body needs approximately 15% 

more oxygen for the production of a given quantity of ATP from fat, compared to carbohydrate. In addition,

as exercise intensity increases there are limitations in the movement of fatty acids from blood to 

mitochondria, which limits the amount of fat oxidation during high-intensity exercise [6] . 

METHODS 

Subjects 

The subjects in this investigation were 10 adults who regularly participate in gym-based fitness activities. 

Table 3 presents the subjects’ descriptive characteristics. At the time of the study, the subjects completed 

an average of five fitness sessions per week. All subjects were familiar with ‘BODYPUMP’ aerobics, 

having participated at least once per week for an average of four years. Exercise histories were obtained 

from the subjects prior to the first testing session. All subjects completed Informed Consent documents in 

accordance with University of Auckland policies. 

Table 3: Subject characteristics 

Age 

(years) 

Mass 

(kg) 


Mean (SD) 

Height 

(cm) 

VO2 Max 

(ml/kg/min) 

Max heart rate 

(beats/min) 

All subjects 32.7 (4.2) 71.1 (13.3) 171.4 (6.5) 50.1 (8.9) 182 (9) 

Males only 31.1 (3.5) 79.5 (12.0) 175.0 (6.0) 52.6 (11.6) 186 (10) 

Females only 34.3 (4.5) 62.6 (8.6) 167.8 (5.3) 47.6 (5.1) 179 (6) 

Procedures 

Each subject reported to the laboratory three times, including a BODYPUMP session, a 60-minute 

session of cycling, and a VO2 max test. The cycling session was included to provide a comparison between 

BODYPUMP and a traditional gym-based mode of exercise known to be effective in consuming calories. 

Body mass was assessed to the closest 0.1 kilogram, and height was measured to the nearest 0.5 

centimeter. 

Metabolic data were collected using indirect calorimetry. The subjects breathed through a Hans Rudolph 

mouthpiece connected to a Hans Rudolph, two-way, non-rebreathing valve (Kansas City, MO), and wore a 

nose clip. Inspired air was measured using a K520 flow transducer (KL Engineering, Sylmar, CA). Expired 

gases were sampled every 60 seconds from a 5-liter mixing chamber and analyzed using Ametek S-3 A1 

oxygen and CD-3A carbon dioxide (CO2) analyzers. Prior to each test, the oxygen and CO2 analyzers were 

calibrated using a gas mixture of known concentration. The analyzers and flow transducer were interfaced 

through an 8bit A/D converter to an IBM-compatible computer. Ventilation, oxygen consumption, CO2 

production, and respiratory exchange ratio were calculated and displayed using Ametek OCM-2 Oxygen 

Uptake System Software. Heart rate was monitored using a telemetric system (Vantage XL, Polar Electro, 

Finland).

For the BODYPUMP and cycling sessions, caloric consumption per minute and the percentage 

contribution from fat and carbohydrate were calculated from the oxygen consumption and respiratory 

exchange ratio (RER) values obtained during the exercise tests, using the table of non-protein respiratory 

quotients provided by Peronnet and Massicotte (1991) [13] 


Each subject performed a BODYPUMP aerobics class under the individual instruction of a Les Mills 

employee. The same instructor and class program was used for all subjects. The subject selected the 

weights used for each segment of the class. The session lasted an average of 57 minutes including the 

warmup and cooldown periods. Expired air was collected for the duration of the class (including warmup 

and cooldown). 

Cycling 

Subjects performed 60 minutes of continuous cycling on a Monark 824E cycle ergometer. The first and final 

5 minutes were performed at a power output of 1.5 Watts per kilogram body weight for males and 1.2 Watts 

per kilogram for females. From the sixth through to the 55 th minute, subjects worked at 2.0 and 1.6 Watts 

per kg for males and females, respectively. Cadence was maintained at 85-90 rpm. 

VO2 Max Test 

The VO2 max test was performed on the Monark 824E cycle ergometer using a continuous, step protocol. 

The starting load was 85W with step increments of 25W (males) and 17W (females) and step duration of 1 

minute. Subjects continued until volitional exhaustion. To represent VO2 max, all subjects achieved the 

following criteria: 1) attainment of a heart rate within 10 beats per minute of age-predicted maximum (using 

the equation 220 minus age in years); and 2) a respiratory exchange ratio of 1.10 or greater [7] . 

Results 

Heart rate and oxygen consumption values during BODYPUMP and cycling are presented in Tables 4-6 

below. The mean oxygen consumption (expressed relative to body weight) during the BODYPUMP 

sessions was 20.2 ml/kg/min for all subjects combined and 21.5 ml/kg/min, and 19.0 ml/kg/min for males 

and females, respectively. The oxygen consumption values for the cycle session were 28.8, 29.4 and 28.2 

ml/kg/min for all subjects, males and females, respectively. 

Subjects exercised at an average intensity of 40.7% of their VO2 max during the BODYPUMP session. 

The values for males and females separately were 41.6% and 39.8%. Intensity values during the bike 

session were 60.3%, 58.7%, 59.2% of VO2 max for all subjects, males and females, respectively. Subjects 

spent an average of 9.8 minutes above 50% VO2 max during the BODYPUMP session when expressed 

as a group and 11.6 and 8.0 minutes respectively, when separated into males and females. Subjects spent 

an average of 1.9 minutes above 70% VO2 max during the BODYPUMP session when expressed as a 

group and 3.2% and 0.6% for males and females, respectively. 


The average heart rate during the BODYPUMP session was 135.4 beats per minute for the group, and 

138.2 and 132.6 for males and females, respectively. During the cycle session these values were 134.1, 

136.5 and 131.6 beats per minute for the group, males and females. Subjects spent an average of 38.8 

minutes above 70% of maximum heart rate during the BODYPUMP session when expressed as a group 

and 37.4 and 40.2 minutes when separated into males and females. During the cycle session these values 

were 33.6, 32.4 and 34.8 minutes for the group, males and females, respectively. The relatively high heart 

rates relative to oxygen consumption during BODYPUMP are explained in the discussion. 

Table 4: Oxygen consumption and heart rate for all subjects during BODYPUMP and cycle 

sessions 



Mean (SD) 

Cycle 

Mean (SD) 

Oxygen consumption (ml/kg/min) 20.24 (3.61) 28.77 (3.24) 

Average percentage of VO2 max 40.7 (5.3) 60.3 (12.3) 

Number of minutes above 50% VO2 max 9.8 (6.1) 45.7 (19.0) 


Average heart rate 135.4 (12.8) 134.1 (19.33) 

Average percentage of maximum heart rate 74.2 (4.7) 73.4 (8.7) 

Average number of minutes above 70% maximum heart rate 38.8 (9.4) 33.6 (27.7) 

VO2 max and maximum heart rate as measured on the cycle during the maximum test 

Table 5: Oxygen consumption and heart rate for male subjects during BODYPUMP and cycle 

sessions 


Mean (SD) 

Cycle 

Mean (SD) 


Average percentage of VO2 max 41.6 (5.6) 58.7 (17.6) 






VO2 max and maximum heart rate as measured on the cycle during the maximum test

Table 6: Oxygen consumption and heart rate for female subjects during BODYPUMP and cycle 

sessions 



Mean (SD) 

Cycle 

Maen (SD) 


Average percentage of VO2 maxϒ 39.8 (5.4) 59.2 (5.6) 






VO2 max and maximum heart rate as measured on the cycle during the maximum test 

Caloric expenditure and substrate utilization during BODYPUMP and cycling are presented in Tables 7-9 

below. Subjects burned an average of 411.0 calories during the BODYPUMP session when expressed 

as a group and 483.1 and 338.9 respectively, when separated into males and females. This equated to 7.2, 

8.4 and 5.9 calories per minute for the group, males and females, respectively. The higher values for the 

men are related primarily to their greater body weight. The maximum number of calories burned, were 424 

for a female, and 603 for a male. 

The BODYPUMP session led to the consumption of 70.0, 88.6 and 51.5 calories of fat and 340.9, 394.4 

and 287.4 calories of carbohydrate for the group, males and females, respectively. This equated to 16.7% 

fat and 83.3% carbohydrate for the group as a whole, 18.6% fat and 81.4% carbohydrate for the males, 

and 14.9% fat and 85.1% carbohydrate for the females. 

Subjects burned an average of 623.3 calories during the cycling session when expressed as a group and 

706.3 and 540.2 respectively, when separated into males and females. This equated to 10.5, 12.0 and 9.0 

calories per minute for the group, males and females, respectively. The cycle session led to the 

consumption of 169.5, 182.1 and 157.0 calories of fat and 453.7, 524.3 and 383.2 calories of carbohydrate 

for the group, males and females, respectively. This equated to 27.3% fat and 72.7% carbohydrate for the 

group as a whole, 26.4% fat and 73.6% carbohydrate for the males only and 28.2% fat and 71.8% 

carbohydrate for the females only.

Table 7: Fuel utilization for all subjects during BODYPUMP and cycle sessions 



Mean (SD) 

Cycle 

Mean (SD) 

Total calories burned 411.0 (99.3) 623.3 (141.4) 

Calories per minute 7.2 (1.6) 10.5 (2.5) 

Total calories of fat consumed 70.0 (32.9) 169.5 (74.6) 

Total calories of carbohydrate consumed 340.9 (74.4) 453.7 (113.5) 

Percentage of total calories from fat 16.7 (5.3) 27.3 (10.6) 

Percentage of total calories from carbohydrate 83.3 (5.3) 72.7 (10.6) 

Table 8: Fuel utilization for male subjects during BODYPUMP and cycle sessions 


Mean (SD) 

Cycle 

Mean (SD) 





Percentage of calories from fat 18.6 (5.3) 26.4 (7.8) 

Percentage of calories from carbohydrate 81.4 (5.3) 73.6 (7.8) 

Table 9: Fuel utilization for female subjects during BODYPUMP and cycle sessions 


Mean (SD) 

Cycle 

Mean (SD) 





Percentage of calories from fat 14.9 (5.0) 28.2 (13.7) 

Percentage of calories from carbohydrate 85.1 (5.0) 71.8 (13.7) 

Table 10 presents a summary of key results for oxygen consumption, caloric expenditure, and substrate 

utilization during BODYPUMP.

Table 10: Summary of key results: BODYPUMP 

VO2 

(ml/kg/min) 


% VO2 Max Total Kcal Kcal/min % CHO % Fat 

All subjects 20.2 40.7 411.0 7.2 83.3 16.7 

Men 21.5 41.6 483.1 8.4 81.4 18.6 

Women 19.0 39.8 338.9 5.9 85.1 14.9 

Blood Lactate Analysis 

To ensure that gas analysis during the BODYPUMP sessions adequately captured total caloric 

utilization, blood lactate samples were taken from seven participants immediately pre- and post a typical 

BODYPUMP class. This was to determine whether subjects had returned to near-resting lactate levels by 

the end of the cooldown. Seven randomly selected individuals (three females, four males) provided 

fingertip blood samples that were analyzed using an Accusport Blood Lactate Analyzer (refer to Table 11). 

Both the moderate elevation in blood lactate concentration at the cessation of exercise, and previous 

studies on EPOC suggest that additional calories are utilized above and beyond those calculated from the 

results of gas analysis (see discussion). 

Table 11: Blood lactate concentration before and after BODYPUMP session 

Discussion 

Subject Before class After class 

1 2.4 3.1 

2 2.1 5.4 

3 2.2 3.0 

4 1.9 3.1 

5 2.4 3.3 

6 2.0 2.7 

7 2.8 4.6 

MEAN 2.3 3.6 

BODYPUMP is a high-repetition, resistance training, choreographed exercise program. The potential 

benefits of BODYPUMP include: improved muscular endurance, increased aerobic fitness, fat weight 

loss, and maintenance of, or increases in, lean body mass. The present study investigated the aerobic 

demand and caloric expenditure of a standard session of BODYPUMP. 

The frequency, intensity, duration, and type of exercise determine the effectiveness of an exercise-training 

program in reducing body fat and improving the various components of fitness. The most widely followed

guidelines for health and fitness are issued by the American College of Sports Medicine (ACSM). The 

ACSM’s position standard for the quantity and quality of training for developing and maintaining aerobic 

fitness, body composition, and muscular strength and endurance in healthy adults includes the following 

recommendations: 

Frequency of training: 3-5 days per week 

Intensity of training: 60-90% of maximum heart rate or 50-85% of maximum oxygen uptake 

Duration of training: 20-60 minutes of continuous aerobic activity 

Mode of activity: Any activity the uses large muscle groups, can be maintained continuously, and is 

rhythmical and aerobic in nature 

Resistance training: Strength training of moderate intensity, sufficient to develop and maintain fat-free 

weight should be an integral part of an adult fitness program. One set of 8-12 repetitions of 8-10 exercises 

that condition the major muscle groups at least two days per week is the recommended minimum. 

BODYPUMP is an effective form of training that fulfills the majority of the ACSM criteria in a one hour 

session. This section discusses the implications of the results of the present study for the physiological 

benefits of BODYPUMP. 

Aerobic Intensity 

Subjects worked at an average of 74.2% of maximum heart rate and 40.7 % of maximum aerobic capacity 

during the BODYPUMP session. These values were similar when males and females were considered 

as a group, and separately. Although the average heart rate during BODYPUMP was high enough to 

meet the ACSM recommendations for developing and maintaining aerobic fitness, the oxygen consumption 

was not. Heart rate during BODYPUMP is elevated disproportionately to oxygen consumption due to the 

pressure effect that occurs during weight-training exercises. For any given level of oxygen consumption, 

heart rate is typically 20% higher for upper body exercise than for lower body exercise such as cycling. 

The average intensity achieved during the cycle session (60.3% of VO2 max and 73.4% of maximum heart 

rate) was higher than that achieved during the BODYPUMP session. The time spent above 50% of VO2 

max and 70% of VO2 max was also higher during cycling. During the BODYPUMP session subjects 

spent 10 minutes above 50% of VO2 max and 2 minutes above 70% VO2 max as compared to 46 minutes 

above 50% VO2 max and 8 minutes above 70% VO2 max for the cycle session. These results indicate that 

the BODYPUMP session provides a low to moderate stimulus to increase aerobic fitness. The implication 

of these results is that BODYPUMP is useful for maintaining aerobic fitness, but does not provide 

sufficient stimulus to improve aerobic fitness in already fit subjects such as those who participated in this 

study. For subjects such as these, two to three days per week of higher-intensity aerobic-based exercise 

would be necessary to improve aerobic fitness. For more sedentary populations, such as middle-aged 


individuals without a history of aerobic training, BODYPUMP would be likely to provide a considerably 

higher relative aerobic demand, which would be sufficient to improve aerobic fitness. 

Energy Expenditure 

A BODYPUMP session utilized an average of 411 calories for the subjects in this study. The males and 

females utilized an average of 483 and 339 calories, respectively. The highest number of calories utilized 

by a male subject during BODYPUMP was 586, while the highest energy expenditure for a female 

subject was 437 calories. Although total calories utilized were greater during the cycle session than during 

the BODYPUMP session, the results indicate that both modes of exercise are effective for promoting 

weight loss. 

The cycle session consumed a greater proportion of fat than the BODYPUMP session (27.3% compared 

to 16.7%) and there were no significant differences between males and females for these values. The 

contribution that fat and carbohydrate make to the fuel mix is dependent on the intensity of the exercise; 

the higher the intensity the smaller the contribution from fat. The BODYPUMP class required intermittent 

bursts of high-intensity, effort, which used exclusively carbohydrate as fuel. In contrast, the cycle session 

was a period of consistent moderate-intensity exercise which allowed a larger contribution from fat. 

However as previously explained, it is the number of calories burned rather than the source of those 

calories which determines energy balance and weight loss. 

The magnitude of excess post-exercise oxygen consumption’s (EPOC) contribution to caloric expenditure 

during BODYPUMP was not measured. The results of the studies presented in Table 2, however, 

suggest that for an hour of exercise similar to BODYPUMP the expected caloric expenditure related to 

EPOC would be approximately 15% of total caloric expenditure. EPOC would, therefore, be expected to 

contribute approximately an additional 62 calories to the average of 411 calories utilized by the subjects in 

this study, increasing total caloric expenditure due to a session of BODYPUMP to 473. Including the 

contribution of EPOC would increase total caloric expenditure due to a session of BODYPUMP to an 

average of 556 calories for the males, and 390 for the females. The number of BODYPUMP sessions 

required to lose one kilogram of body fat (7,700 calories), therefore, is 16.3 for the average subject, 13.8 for 

the average male, and 19.7 for the average female in this study. A subject who did not change his or her 

dietary intake, and who added three sessions of BODYPUMP per week could expect to lose 1 kilogram 

of body fat in four to six weeks. 


Additional Benefits of BODYPUMP 

Additional benefits of BODYPUMP include likely improvements in muscular endurance, maintenance of 

lean body mass and social interaction. Muscular endurance is defined as the ability of a muscle to 

repeatedly produce force over time and resist fatigue [17] and can be increased most effectively by low- 

resistance, high-repetition exercise. Although the effect of BODYPUMP sessions on muscular endurance 

was not measured in this study, the moderate load, high-repetition nature of BODYPUMP fits the 

requirements for improving muscular endurance. Measurement of this benefit is an area for future 

investigation. The use of challenging loads by some individuals during BODYPUMP sessions may result 

in absolute strength gains and muscular hypertrophy. It is unlikely that strength gains and hypertrophy 

would occur for already fit subjects such as those who participated in the present study; however, for 

individuals without a history of resistance training, BODYPUMP may provide sufficient stimulus to elicit 

strength gains. 

To maintain and/or increase lean body mass requires stimulation of muscle mass. Although the present 

study did not track lean body mass over time, the resistance exercises performed during BODYPUMP 

certainly appear to be sufficient for the maintenance of lean body mass. The whole body resistance training 

of BODYPUMP suggests that this program is more effective in maintaining or increasing lean body mass 

than is cycling. This is an additional area for future investigation. 

Finally, the social interaction provided by a BODYPUMP class provides enjoyment and a motivating 

environment which encourages adherence to the exercise program. The greatest health and fitness 

challenge to the average individual is maintaining a regular exercise routine. The positive social 

atmosphere of a BODYPUMP session is likely to lead to enhanced enjoyment and improved adherence 

which will lead to greater long-term benefits to health and fitness. 


References 

1. Chad, K.E. and Wenger, H.A. (1985). The effects of duration and intensity on the exercise and 

post-exercise metabolic rate. The Australian Journal of Science and Medicine in Sport. 17(45):14-18. 

2. Dawson, B., Straton, S. and Randall, N. (1996). Oxygen consumption during recovery from 

prolonged sub-maximal cycling below the anaerobic threshold. Journal of Sports Medicine and Physical 

Fitness. 36:77-84. 

3. Elliot, D.L., Goldberg, L. and Kuehl, K.S. (1992). Effect of resistance training on excess post- 

exercise Oxygen consumption. Journal of Applied Sport Science Research. 6(2):77-81 

4. Frayn, K.N. (1983). Calculation of substrate oxidation rates in vivo from gaseous exchange. 

Journal of Applied Physiology. 55(2):628-634. 

5. Fox, E.L., Bowers, R.W. and Foss, M.L. (1993). The Physiological Basis for Exercise and Sport. 

(Fifth edition). Brown and Benchmark: Madison, Wisconsin. 

6. Hawley, J.A., Brouns, F. and Jeukendrup, A. (1998). Strategies to enhance fat utilization during 

exercise. Sports Medicine. Apr; 25(4), p241-257. 

7. Issekutz, B., Birkhead N.C and Rodahl K (1962) Use of respiratory quotients in assessment of 

aerobic work capacity. J. Appl. Physiol. 17:47-57. 

8. Martin, W.H. (1997). Effect of endurance training on fatty acid metabolism during whole body 

exercise. Medicine and Science in Sports and Exercise. 29:635-639. 

9. Melby, C.L. and Hill, J.O. (1999). Exercise macronutrient balance, and body weight regulation. 

Sports Science Exchange. SSE #72, 12(1). 

10. Mole, P.A. (1990). Impact of energy intake and exercise on resting metabolic rate. Sports 

Medicine. 10(2):72-87. 

11. Neiman, D.C., Haig, J.L., De Guia, E.D., Dizon, G.P.and Register, U.D. (1988). Reducing diet and 

exercise training effects on resting metabolic rates in mildly obese women. Journal of Sports Medicine and 

Physical Fitness. 28:79-88. 

12. Olds, T.S. and Abernethy, P.J. (1993). Post-exercise oxygen consumption following heavy and 

light resistance exercise. Journal of Strength and Conditioning Research. 7(3):147-152. 


13. Peronnet, F. and Massicotte, D. (1991). Table of non-protein respiratory quotient: An update. 

Canadian Journal of Sport Science. 16(1):23-29. 

14. Puhl, S.M. & Clark, K. (1992). Exercise intensity and body fat loss. National Strength and 

Conditioning Association Journal. 14(6):16-18. 

15. Quinn, T.J., Vroman, N.B. and Kretzer, R. (1994). Post-exercise oxygen consumption in trained 

females: effect of exercise duration. Medicine and Science In Sports and Exercise. 26(7):908-913. 

16. Sedlock, D.A., Fissinger, J.A. and Melby, C.L. (1989). Effects of exercise intensity and duration on 

post exercise energy expenditure. Medicine and Science in Sports and Exercise. 21:626-631. 

17. Zatsiorsky, V.M. (1995). Science and Practice of Strength Training. Human Kinetics; Champaign, 

Il. 

“Creating life-changing fitness experiences everytime, everywhere” 


An An Attitudi Attitudinal Attitudi nal Study Study on on the 

the 

BODYPUMP BODYPUMP WORKOUT WORKOUT 

International Survey Company A C Nielsen (1999) 

Objectives 

This research examines the opinions and attitudes towards the BODYPUMP workout amongst regular 

attendees. For the purposes of this study, a regular attendee comprises anyone who has been going to 

BODYPUMP classes twice a week or more, on average, for at least three months. 

To examine the opinions and attitudes of these people, we asked: 

a) The degree to which people enjoyed a variety of different aspects of the BODYPUMP workout; 

b) The different benefits people believe they gain from attending BODYPUMP classes, including 

muscle toning and fat loss; 

c) The incidence of injuries incurred by regular participants and which parts of the body were injured; 

e) A variety of demographic information, including age, gender and other sporting activities. 

Methodology 

The target group for this research was current members of Les Mills World of Fitness in Auckland who 

were regular BODYPUMP class attendees. 

Our target audience was reached using Les Mills’ membership list and screening for people who were 

regular attendees of BODYPUMP. 

Two questionnaires were developed in consultation with Les Mills International. Both were conducted using 

Computer Assisted Telephone Interviewing (CATI) and allowed for up to three call-backs to phone eligible 

contacts before replacing one contact with another. All interviewing was conducted in the evenings and 

during the weekends. 

The first questionnaire lasted 10 minutes and covered the majority of the research objectives, while the 

second lasted 5 minutes and was designed to get greater detail and an annualized rate on injuries. 

Interviewing was conducted between 17 March and 7 April 1999 for the initial questionnaire and between 

31 May and 6 June 1999 for the second. The final sample size was 200 respondents. 


Results 

Enjoyment of BODYPUMP 

Gym members were very positive about their enjoyment of the BODYPUMP classes. At least 90% 

agreed that: 

a) The routines are easy to follow (97%); 

b) BODYPUMP classes provide a challenging workout (93%); 

c) The instructors are friendly and helpful (90%). 

In addition, agreement with the remaining enjoyment factors was over 70%. 

a) BODYPUMP classes are fun (89%); 

b) BODYPUMP classes have improved my overall feeling of well-being (86%); 

c) Attending BODYPUMP classes improves my performance in other sports and exercise activities 

(72%). 

Even amongst statements with less than 90% agreement, the level of disagreement was very low. People 

who didn’t agree with a statement preferred to say they neither agreed nor disagreed. 

Benefits of BODYPUMP 

Gym members were asked how strongly they felt they received certain physical benefits from attending 

BODYPUMP. It is important to remember the responses represent perceived benefits and not 

necessarily actual benefits received. 

Quite clearly, the two benefits members most strongly felt they got from BODYPUMP related to muscular 

development: 

a) Improved strength (95%); 

b) Improved muscle tone (93%). 

Respondents also felt that the benefit of lower body fat applied quite strongly to them. Half were positive, 

saying this benefit applied to them (52%), and a further 39% were neutral. Only 8% said they didn’t feel this 

benefit applied to them. 

Of the remaining statements concerning the physical benefits of BODYPUMP, the proportions of people 

who felt that each benefit applied to them were as follows: 

a) Improved cardiovascular fitness (34%); 

b) Improved coordination (30%); 


c) Lower body weight (29%); 

d) Improved flexibility (26%). 

Except for the strength/muscle tone benefits, there were relatively high levels of neutral ratings across all 

the statements. This suggests people are often unsure whether their body has improved. It is possible they 

are mistaking an increase, or lack of decrease, in body weight brought about by better muscle mass as 

meaning they haven’t lost fat. 

Injuries Resulting From BODYPUMP 

The injury rate amongst BODYPUMP attendees was measured by the incidence of significant injuries 

sustained in the past three months as a direct result of attending a BODYPUMP class. A significant 

injury was defined as an injury that required professional attention or one that prevented a respondent from 

attending BODYPUMP classes for at least two weeks. 

Across the sample as a whole, the three-month rate of injury was 1.57%. Of the three people injured (on a 

base of 188), two injured their backs and one their shoulder. All three sought professional attention for 

their injuries - one consulted a physiotherapist, one a masseur, and the third an orthopedic specialist. 

Likelihood of Continuing BODYPUMP Classes 

Ninety two percent of respondents said they were likely to continue going to BODYPUMP classes in the 

next six months; 84% of the sample said they were very likely to continue going. 

Amongst this 92%, most (79%) said they would continue to attend BODYPUMP with the same degree of 

regularity as they do now. 

A positive result is that amongst the remainder of these respondents, 17% said they planned to increase 

their frequency while only 3% said they planned to decrease it. 

The intention to increase BODYPUMP class frequency is more likely amongst younger (under 35 years, 

23%) rather than older (35 years and older, 8%) members. 

Comments on BODYPUMP 

Three-quarters of the respondents (78%) provided open-ended comments on BODYPUMP. 

Amongst people who made a comment, the majority were very positive: 

a) Great class/very happy with class/excellent (40%); 

b) Great instructors (19%); 

c) Gives good results/effective (14%); 

d) Interesting/fun/avoids monotony (11%); 


e) Music is good/they regularly vary the music (7%); 

f) Caters to your fitness level/able to work out at your own level (6%). 

The more negative comments included: 

• Pay more attention to people’s technique/give tips on technique (14%) 

• Routines are monotonous/need to vary program sometimes (10%) 

• Classes too crowded/large (8%) 

• Music boring/change the music/better variety of music (7%) 

• Instructors inconsistent/some good, some poor (7%). 

Below are some actual verbatim responses that Les Mills International recorded. All comments have been 

attributed with respondents’ permission, knowing that the comments may be used for promotional 

purposes. 

“I think they are absolutely fantastic, keep it up. I think it’s great. I want to make sure they keep it up. I’ve 

had two babies and it [BODYPUMP] has helped me get back into shape, it helped my overall stamina 

during pregnancy, and helped me get my body back after having the babies. It helped my overall fitness 

levels. It helped me get through the pregnancy.” 

- Annika Lane 

“BODYPUMP rocks for getting all-round toning up of the muscles. Having worked out for about 16 years 

it has been the most efficient way of converting my fat to muscle.” 

- Simon Clark 

“It’s [BODYPUMP] just awesome. You can work at your own level. It’s a little bit social which is good.” 

- Sharon Amphlett 

“I think overall it’s [BODYPUMP] fantastic, especially when you’re short on time. It gives you the muscle 

tone and fitness so if you don’t have much time it’s an excellent workout.” 

- Lauren Barriball 

It [BODYPUMP] is the best thing I’ve ever done in terms of workout. If you haven’t done it you have to do 

it, it’s addictive.” 

- Tracey Thompson 


Other Sporting Activities BODYPUMP Members Take Part In 

Other gym-based activities * (53%), running (32%) and walking (27%) are the main activities outside of 

BODYPUMP that members take part in. 

Looking at gym-based activities in more detail, 25% of the sample listed their activities outside of 

BODYPUMP as general gym exercising (eg circuit training, boxing, etc.), 21% said aerobics and just 7% 

said weight training. 

* Gym-based activities include mentions of gym, aerobics and weights. 


Summary Discussion 

The most positive aspects of BODYPUMP based on the findings of this report are the high levels of 

enjoyment amongst attendees and the physical benefits of improved muscle tone and strength. 

Attendees appeared unsure about whether BODYPUMP had helped them with other aspects of their 

physical conditioning. It is possible, as was stated in the text, that attendees are mistaking an increase or 

lack of decrease in body weight brought about by an increase in muscle mass as meaning they haven’t lost 

fat. It may be that people need to be made more aware of this idea and the need to judge their progress by 

body composition and body fat readings, as well as their ability over time to progress through each 

BODYPUMP workout. 

BODYPUMP has a low injury rate which suggests a very user-friendly format well suited to people who 

attend the classes. People did comment, however, on wanting to see instructors help people with poor form 

Just 9 out of 10 people said they were likely to continue going to the classes. Younger members are more 

likely then older members to actually consider increasing the frequency of attendance at BODYPUMP. 

This is a positive sign – these are the people who have the potential to be the longest-serving 

BODYPUMP class attendees. 

BODYPUMP members appear to enjoy aerobic activity even when they are not attending classes – other 

gym work (emphasis on the aerobic side) and running and walking. 


THE PHYSICAL AND PSYCHOLOGICAL 

RESPONSE TO 13 WEEKS oF STRUCTURED 

GROUP-FITNESS EXERCISE IN 

UNTRAINED INDIVIDUALS 

LYTHE, J, PFITZINGER, P & HO, D. 

UNISPORTS CENTER FOR SPORT PERFORMANCE, UNIVERSITY OF AUCKLAND (2000) 

Introduction 

Group exercise fitness classes have grown in popularity over the past 20 years. Aerobics is now a term that 

encompasses a broad range of these group exercise classes from bench step classes to choreographed 

Martial Arts classes. A leading organization in the aerobics market is Les Mills International (LMI). LMI have 

developed the Les Mills Body Training Systems product range which includes BODYPUMP, 

BODYSTEP, BODYATTACK, BODYCOMBAT, and RPM. The acute effects (aerobic intensity and 

caloric expenditure) of these classes have been previously studied [1] but the longitudinal effects of 

participation have not. The purpose of this study was to measure the effect of 13 weeks of group exercise 

classes on the physical and psychological condition of untrained adults. 

Methods 

A total of 150 subjects volunteered for the study. They were randomly selected from 500 individuals that 

responded to an advertisement in the national newspaper. Subjects were required to be between the ages 

of 16 and 60 and to have been inactive for a period of at least six months. The characteristics of the 

subjects at the commencement of the study are shown below (Table 1). 

Table 1: Descriptive characteristics of subjects who commenced the study 


All Subjects Males Females 

n 150 68 82 

Age (yrs) 35.0 (10.1) 35.9 (9.7) 34.2 (10.4) 

Weight (kg) 78.5 (16.1) 88.1 (12.4) 70.6 (14.3) 

Height (cm) 171.6 (10.0) 179.3 (8.8) 165.2 (6.8) 

All subjects were given a detailed written information pack as well as a verbal explanation of the study 

before being asked to participate. Informed consent was obtained from every subject. The study lasted 15 

weeks and a timeline of events is shown below (Figure 1).

Figure 1: Project timeline 

Week 1 

Pre-test 

Test Descriptions 

All subjects performed a battery of fitness tests prior to the intervention being commenced. A number of 

testing sessions were scheduled over the course of a week to enable all subjects to be tested at their 

convenience. Each session was of approximately 90 minutes duration and was attended by 3-10 subjects. 

Tests were performed at the facilities of UniSports Center for Sport Performance by suitably qualified staff. 

The tests measured aerobic fitness, body composition, upper body strength and muscular endurance, 

lower body strength and muscular endurance and psychological well-being. During all tests the 

administrators provided consistent verbal encouragement. Details of each test are given below. 

Multi-stage shuttle run test 

The multi-stage shuttle run test or ‘beep test’ provides a very simple measure of aerobic endurance. The 

test requires subjects to run back and forth between two lines that are 20 meters apart. Subjects must run 

at a pace that is set by an audiotape. As the test progresses the subjects must increase their running 

speed to stay at the pace of the tape. The point that each subject can no longer keep up with the pace is 

the end of the test. The test administrator stops a subject when they fall behind the beep on two 

consecutive lengths. Subjects receive a numeric score that indicates the number of 20-meter lengths 

successfully completed. 

Body composition 

Body mass was measured to the nearest 0.1 kg using Seca alpha electronic scales. Height was measured 

to the nearest 0.5 cm using a stadiometer. Skinfolds were taken using Slimguide calipers in accordance 

with ISAK procedures at the following sites: triceps, subscapular, biceps, iliac crest, supraspinale, 

abdominal, thigh and calf. A sum of eight skinfolds was used as the primary measure of body fatness. Two 

additional body composition variables were then derived. Body mass index (BMI) was calculated using the 

following formula: 

BMI = weight (kg) / height (m 2 ). 

Weeks 2-14 

Intervention 

Percentage of body fat was calculated first by using the formula for body density provided by Durnin and 

Womersley (1974) and then the formulae for percent body fat by Siri (1961). 

BD (males) = 1.1765 – 0.0744 (log10∑S4skinfolds) 


Week 15 

Post-test

BD (females) = 1.1567 – 0.0717(log10∑S4skinfolds) 

% BF = (4.95/BD-4.50) x 100 

These formulae were chosen as they best represented the mix of age and race provided in the sample. [4] 

Upper body strength and muscular endurance 

The bench press exercise was used as a measure of both upper body strength and upper body muscular 

endurance. This exercise was performed with a barbell and weights. After a period of familiarization the 

subjects, six repetition maximum (6RM) was determined by having them perform sets of six repetitions at 

progressively increasing loads. Subjects used a slightly-wider-than-shoulder-width grip on the bar and were 

required to keep their lower back and hips in contact with the bench during the lowering and pressing 

movements. The 6RM was the heaviest load successfully lifted for six repetitions. Muscular endurance was 

measured by having the subject complete as many repetitions as possible using a load equal to 70% of 

their 6RM. During both tests a movement tempo of 1 second to raise the weight and 1 second to lower the 

[5, 6] 

weight was enforced. 

Lower body strength and muscular endurance 

The horizontal leg press exercise was used as a measure of both lower body strength and lower body 

muscular endurance. This exercise was performed using a pin-loaded machine (Fitness Works, Auckland). 

Subjects were required to perform a specific range of motion on every repetition. The range of motion was 

from 90 o of knee flexion to 5 o of knee flexion. After a period of familiarization for the subjects, six repetition 

maximum (6RM) was determined by having each subject perform sets of six repetitions at progressively 

greater loads. The 6RM load was the heaviest load successfully lifted for six repetitions. Muscular 

endurance was measured by having the subject complete as many repetitions as possible using a load 

equal to 70% of their 6RM. As for the bench press, a movement tempo of 1 second to raise the weight and 

1 second to lower the weight was enforced. 

Psychological state 

Psychological state was assessed using a questionnaire (Refer to Appendix B). Subjects were required to 

rate themselves on a five-point scale with regard to 10 positive and 10 negative emotions. The 

questionnaire was scored by adding together the ratings from the positive questions then subtracting the 

ratings from the negative questions. This system provided a scoring range of –40 to +40. 

Intervention 

This was a single intervention study with an exercise program being the intervention. 


Group exercise classes 

From the start of week 2 until the end of week 14 (13 weeks of activity) subjects were required to attend 

group exercise classes at the facilities of Les Mills World of Fitness in Auckland. Subjects were randomly 

allocated into five groups and each group performed a different group exercise class. The groups were: 

BODYPUMP, BODYSTEP, BODYATTACK, BODYCOMBAT and RPM. Subjects were only 

permitted to perform the class to which they were allocated. They were required to attend between two and 

five sessions per week and must have performed a total of 32 sessions by the end of the 14 th week to be 

included in the analysis. Introductory sessions were offered to all participants to ensure that they were 

skilled in the movements of each class prior to commencement of the program. 

Diet 

Subjects were instructed not to change their diet. A three-day diet record was obtained for a sample of 

subjects during week 1 and during week 14. These diet records were compared to see if caloric intake or 

composition was significantly altered during the study. 

Data Analysis 

All test data was entered into a specially designed Microsoft Excel spreadsheet. Each group’s results were 

pooled so that pre- and post-intervention data could be compared. T-tests were used to determine if post- 

intervention test data was significantly different to pre-intervention data. 

Results 

Table 2: Initial descriptive characteristics of subjects who completed the study 


All subjects Males Females 

n 79 37 42 

Age (yrs) 36.1 (9.6) 36.1 (8.1) 36.1 (10.9) 

Weight (kg) 78.1 (15.7) 87.5 (11.3) 70 (14.8) 

Height (cm) 171.4 (10.2) 179.6 (7.8) 164.3 (6.1)

Table 3: Initial descriptive characteristics of subjects who performed BODYPUMP and completed 

the study 



n 40 16 24 

Age (yrs) 40.5 (10.9) 41.1 (8.8) 40 (12.3) 

Weight (kg) 77.0 (16.5) 88.1 (11.1) 69.1 (15.3) 

Height (cm) 170.8 (11.0) 180.8 (8.1) 163.7 (6.3) 

Table 4: Initial descriptive characteristics of subjects who performed BODYATTACK and 

completed the study 


n 8 5 3 

Age (yrs) 29.9 (6.1) 29.4 (6.2) 30.7 (7.1) 

Weight (kg) 83.1 (16.7) 90.2 (16.1) 71.2 (11.4) 

Height (cm) 171.6 (6.8) 175.1 (4.3) 165.7 (6.5) 

Table 5: Initial descriptive characteristics of subjects who performed BODYSTEP and completed 

the study 


n 11 8 3 

Age (yrs) 34.0 (5.4) 35.9 (3.0) 29.0 (8.0) 

Weight (kg) 82.4 (17.4) 89.9 (13.6) 62.3 (5.2) 

Height (cm) 176.6 (11.4) 181.2 (8.3) 164.2 (9.8) 

Table 6: Initial descriptive characteristics of subjects who performed BODYCOMBAT and 

completed the study 


n 10 3 7 

Age (yrs) 31.0 (3.6) 30.0 (1.7) 32.3 (4.2) 

Weight (kg) 74.1 (9.1) 81.9 (4.3) 67.8 (6.5) 

Height (cm) 168.8 (7.8) 173.3 (9.3) 165.1 (4.6) 

Table 7: Initial descriptive characteristics of subjects who performed RPM and completed the 

study 


N 10 5 5 

Age (yrs) 31.2 (5.8) 31.0 (4.9) 31.4 (7.3) 

Weight (kg) 86.5 (14.3) 88.4 (9.6) 84.6 (18.9) 

Height (cm) 173.9 (8.5) 179.7 (6.8) 168.2 (5.8)

Table 8: Change in skinfolds of subjects as a result of the intervention 


BODYATTACK 

BODYCOMBAT 

BODYSTEP 

RPM 


Mean (SD) sum of 8 skinfolds (mm) 

Pre Post Change T-test 

Group 176.2 (59.4) 145.3 (50.4) 29.9 (22.9) 0.000 

Males 152.3 (47.8) 127.5 (45.3) 23.7 (21.7) 0.000 

Females 192.1 (62.0) 157.1 (51.0) 33.8 (23.2) 0.000 

Group 198.4 (52.7) 167.5 (49.4) 31.0 (34.6) 0.039 

Males 189.1 (49.5) 178.6 (56.9) 10.6 (12.7) 0.136 

Females 214.0 (65.0) 149.0 (35.4) 65.0 (32.9) 0.048 

Group 176.4 (62.0) 153.8 (53.8) 22.6 (23.8) 0.015 

Males 122.5 (61.1) 123.2 (61.0) -0.7 (3.9) 0.794 

Females 199.4 (49.6) 166.9 (49.3) 32.6 (21.5) 0.007 

Group 163.7 (40.8) 154.3 (38.9) 9.4 (26.1) 0.259 

Males 159.9 (40.4) 151.4 (39.9) 8.4 (24.6) 0.365 

Females 174.0 (48.9) 162.0 (43.4) 12.0 (35.5) 0.618 

Group 189.2 (62.9) 161.5 (58.9) 27.7 (23.3) 0.005 

Males 139.3 (41.2) 127.2 (50.3) 12.1 (16.6) 0.179 

Females 239.0 (31.3) 195.7 (48.4) 43.3 (18.3) 0.006 

Table 9: Change in percent body fat of subjects as a result of the intervention 


BODYATTACK 

BODYCOMBAT 

Mean (SD) percent body fat 


Group 32.2(5.9) 29.5 (6.4) 2.7 (2.0) 0.000 

Males 27.8 (4.4) 25.0 (5.2) 2.9 (2.7) 0.000 

Females 35.2 (4.9) 32.5 (5.3) 2.6 (1.6) 0.000 

Group 33.0 (4.6) 31.2 (5.3) 1.8 (2.1) 0.039 

Males 31.1 (3.6) 29.5 (4.4) 1.6 (1.4) 0.074 

Females 36.3 (5.4) 33.9 (6.5) 2.3 (3.2) 0.33 

Group 31.7 (8.5) 30.4 (7.6) 1.3 (1.9) 0.054 

Males 22.8 (8.3) 22.8 (7.9) 0.0 (1.1) 0.946 

Females 35.6 (5.2) 33.7 (5.0) 1.9 (1.9) 0.038

BODYSTEP 

RPM 


Group 29.6 (5.1) 29.0 (5.7) 0.6 (2.9) 0.558 

Males 27.6 (3.7) 27.0 (4.9) 0.6 (3.0) 0.581 

Females 34.7 (5.1) 34.4 (4.1) 0.3 (3.3) 0.882 

Group 32.4 (7.7) 30.3 (7.7) 2.2 (2.7) 0.031 

Males 25.8 (4.4) 24.8 (6.8) 1.1 (3.3) 0.512 

Females 39.1 (1.8) 35.8 (3.3) 3.3 (1.5) 0.009 

The results indicate that subjects made an average reduction in body fat (as represented by skinfolds) of 

21.3mm. When expressed in terms of percent body fat the reduction was 2.1%. The BODYPUMP group 

had the largest reduction of the five classes. Skinfolds decreased by 29.9mm and percent body fat 

decreased by 2.7%. This group also had the largest sample (40 subjects) which gave the results a high 

level of statistical and practical significance. Males and females had similar percent body fat reductions in 

the BODYPUMP group with 2.9% and 2.6% reductions respectively. The BODYATTACK group had an 

average decrease in skinfolds of 31.0mm, equal to a reduction of 1.8% body fat. Females had a slightly 

greater decrease in percent body fat than the males (2.3% as compared to 1.8%) but the small sample size 

reduces the power of this observation. The BODYCOMBAT group had an average decrease in skinfolds 

of 22.6mm, equal to a reduction in percent body fat of 1.3%. Within the group, however, it was evident that 

the females were responsible for all the reductions in skinfolds and percent body fat. The males did not 

reduce skinfolds or percent body fat while the females had reductions of 22.6mm and 1.9% respectively. 

The BODYSTEP group decreased skinfolds by 9.4mm, equal to a reduction in percent body fat of 0.6%. 

Both males and females had similar reductions within the BODYSTEP group. The RPM group had an 

average decrease in skinfolds of 27.7mm, equal to a 2.2% decrease in percent body fat. Females 

decreased by a larger amount than males with reductions of 43.3mm and 3.3%, compared to the males 

with 12.1mm and 1.1%. 

Table 10: Change in aerobic fitness as a result of the intervention 


BODYATTACK 

Mean (SD) beep test level 


Group 41.0 (23.4) 46.0 (26.0) 5.1 (6.8) 0.000 

Males 55.3 (23.4) 61.5 (28.5) 6.3 (8.5) 0.009 

Females 31.5 (18.2) 35.7 (18.5) 4.3 (5.6) 0.001 

Group 44.9 (23.6) 58.3 (26.4) 13.4 (8.1) 0.002 

Males 50.2 (26.9) 64.9 (27.9) 14.4 (9.1) 0.024 

Females 36.0 (17.7) 47.7 (25.0) 11.7 (7.4) 0.111

BODYCOMBAT 

BODYSTEP 

RPM 


Group 55.6 (30.6) 66.0 (27.3) 10.4 (8.2) 0.003 

Males 86.7 (30.0) 96.0 (23.6) 9.3 (6.4) 0.128 

Females 42.3 (20.4) 53.1 (16.9) 10.9 (9.3) 0.022 

Group 58.4 (20.8) 72.9 (25.8) 14.5 (10.8) 0.001 

Males 63.4 (21.2) 80.1 (24.1) 16.8 (11.1) 0.004 

Females 45.0 (14.7) 53.7 (23.3) 8.7 (8.7) 0.228 

Group 50.2 (27.6) 59.5 (30.2) 9.3 (10.2) 0.018 

Males 72.4 (19.0) 84.0 (14.5) 11.6 (11.9) 0.095 

Females 28.0 (11.1) 35.0 (18.6) 7.0 (8.9) 0.154 

The results indicate that subjects made an average improvement in beep test score of 7.9 (9.2) lengths. 

The average beep test score improved from 46.8 lengths (standard deviation of 24.9) to 56.1 lengths 

(standard deviation of 27.8). This represents a change in VO2 max from 34.9 (27.1) to 38.2(27.8), an 

improvement of 3.3 (3.8) ml/kg/min. The BODYPUMP group improved from 41.0 (23.4) to 46.0 (26.0) 

lengths. This represents an increase in VO2 max of 2.0 ml/kg/min from 32.6 (26.0) to 34.6 (27.2) ml/kg/min. 

Males from the BODYPUMP group scored higher than females on the beep test although the 

improvements were similar. The average difference in VO2 max between males and females at the 

commencement of the study was 8.6 ml/kg/min or 23.8 lengths of the beep test. The BODYATTACK 

group improved from 44.9 (23.6) to 58.3 (26.4) lengths. This represents an increase in VO2 max of 4.7 

ml/kg/min from 34.2 (26.2) to 38.9 (27.4) ml/kg/min. Similar to the BODYPUMP group, males had higher 

pre and post- scores for the beep test (an average difference in VO2 max at the commencement of the 

study was 5.1ml/kg/min or 14.2 lengths of the beep test.) The BODYCOMBAT group improved from 55.6 

(30.6) to 66.0 (27.3) lengths. This represents an increase in VO2 max of 3.4 ml/kg/min from 38.0(28.9) to 

41.4 (27.7) ml/kg/min. Similar to the BODYPUMP and BODYATTACK groups, males had higher pre 

and post- scores for the beep test (an average difference in VO2 max at the commencement of the study 

was 14.5 ml/kg/min or 44.4 lengths of the beep test). The BODYSTEP group improved from 58.4 (20.8) 

to 72.9 (25.8) lengths. This represents an increase in VO2 max of 4.6 ml/kg/min from 38.9 (22.9) to 43.5 

(27.1) ml/kg/min. BODYSTEP males had higher pre and post- scores for the beep test (an average 

difference in VO2 max at the commencement of the study was 6.3 ml/kg/min or 18.4 lengths of the beep 

test and they also had greater improvements over the 13 weeks. The RPM group improved from 50.2 

(27.6) to 59.5 (30.2) lengths. This represents an increase in VO2 max of 3.3 ml/kg/min from 36.0 (27.7) to 

39.3 (28.8) ml/kg/min. RPM males had higher pre and post- scores for the beep test (an average 

difference in VO2 max at the commencement of the study was 15.5 ml/kg/min or 44.4 lengths of the beep 

test. The improvements over the 13 weeks were similar for males and females.

Table 11: Change in upper body strength as a result of the intervention 


BODYATTACK 

BODYCOMBAT 

BODYSTEP 

RPM 


Mean (SD) 6RM bench press (kg) 


Group 33.0 (14.8) 38.1 (15.0) 5.2 (5.4) 0.000 

Males 47.0 (11.7) 52.8 (10.9) 6.0 (5.8) 0.001 

Females 23.6 (7.5 ) 28.4 (7.5) 4.7 (5.3) 0.000 

Group 36.4 (12.5) 45.8 (19.4) 9.4 (8.6) 0.017 

Males 43.0 (10.8) 54.0 (18.8) 11.0 (8.8) 0.049 

Females 25.3 (4.5) 32.2 (12.7) 6.8 (9.4) 0.340 

Group 41.3 (22.4) 46.7 (24.3) 5.4 (10.5) 0.143 

Males 68.3 (17.6) 69.2 (20.1) 0.8 (3.8) 0.742 

Females 29.7 (11.3) 37.0 (19.7) 7.3 (12.1) 0.163 

Group 45.0 (18.8) 50.1 (21.8) 5.1 (5.5) 0.011 

Males 53.8 (13.4) 60.2 (15.4) 6.4 (5.0) 0.008 

Females 21.7 (3.1) 23.3 (8.5) 1.7 (6.3) 0.693 

Group 43.3 (21.8) 47.5 (22.0) 3.8 (6.0) 0.079 

Males 55.5 (22.4) 59.5 (23.5) 4.0 (6.8) 0.256 

Females 28.1 (6.9) 32.5 (3.5) 3.5 (6.0) 0.271 

Upper body strength as measured using the bench press increased from 37.3 (17.4) kg to 42.8 (18.8) kg. 

The BODYPUMP group increased from 33.0 (14.8) kg to 38.1 (15.0) kg. Although the males had higher 

initial test scores for the bench press the level of improvement was similar with males increasing their 

bench press by 6.0 (5.8) kg and females by 4.7 (5.3) kg. These increases were statistically significant. The 

BODYATTACK group had the largest increase in bench press. Subjects improved from 36.4 (12.5) kg to 

45.8 (19.4) kg, an increase of 9.4 (8.6) kg. Male subjects started at a higher level and increased their bench 

press more than the females. They started at 43.0 (10.8) and increased by 11.0 (8.8) kg as compared to 

the females who started at 25.3 (4.5) and increased by 6.8 (9.4). The increases achieved by 

BODYATTACK males and females were statistically significant. The BODYCOMBAT group increased 

from 41.3 (22.4) kg to 46.7 (24.3) kg, an increase of 5.4 (10.5) kg. Males from the BODYCOMBAT group 

started at a higher level but improved by a much smaller amount than the females. Males started at 68.3 

(17.6) and increased by 0.8 (3.8) kg as compared to the females who started at 29.7 (11.3) kg and 

increased by 7.3 (12.1) kg. Only the increase achieved by the females was statistically significant. The 

BODYSTEP group increased from 45.0 (18.8) kg to 50.1 (21.8) kg, an increase of 5.1 (5.5) kg. Males 

started at a higher level in the bench press and improved to a greater degree than females. Males started

at 53.8 (13.4) and increased by 6.4 (5.0) kg as compared to the females who started at 21.7 (3.1) kg and 

increased by 1.7 (6.3) kg. Only the increase achieved by the males was statistically significant. The RPM 

group increased from 43.3 (21.8) kg to 47.5 (22.0) kg, an increase of 3.8 (6.0) kg. Males and females 

improved to a similar degree. Males started at 55.5 (22.4) and increased by 4.0 (6.8) kg as compared to the 

females who started at 28.1 (6.9) kg and increased by 3.5 (6.0) kg. Neither the male or female group 

increases were statistically significant. 

Table 12: Change in upper body muscular endurance as a result of the intervention 


BODYATTACK 

BODYCOMBAT 

BODYSTEP 

RPM 


Mean (SD) number of repetitions of the bench press at 

70% of 6RM 


Group 18.6 (7.0) 23.6 (7.3) 5.1 (6.2) 0.000 

Males 14.8 (4.6) 18.9 (5.1) 4.3 (6.6) 0.022 

Females 21.1 (7.2) 26.8 (6.9) 5.5 (6.0) 0.000 

Group 15.9 (2.7) 14.5 (5.4) -1.4 (4.2) 0.390 

Males 14.4 (1.9) 11.6 (2.4) -2.8 (3.0) 0.108 

Females 18.3 (2.1) 19.3 (5.8) 1.0 (5.6) 0.790 

Group 15.9 (6.4) 19.2 (4.2) 3.3 (8.6) 0.255 

Males 16.3 (8.4) 17.3 (4.6) 1.0 (13.0) 0.906 

Females 15.7 (6.2) 20.0 (4.0) 4.3 (7.1) 0.162 

Group 15.6 (3.1) 16.8 (4.1) 1.2 (4.7) 0.427 

Males 15.6 (3.7) 16.1 (4.4) 0.5 (5.3) 0.797 

Females 15.7 (1.2) 18.7 (3.2) 3.0 (2.6) 0.188 

Group 17.2 (7.4) 15.6 (3.6) -1.5 (5.9) 0.443 

Males 13.4 (4.3) 13.2 (2.9) -0.2 (2.6) 0.871 

Females 22.0 (8.1) 18.5 (1.9) -2.8 (8.2) 0.504 

For the group as a whole upper body muscular endurance, as measured by the number of repetitions 

performed on the bench press at 70% of 6RM, increased from 17.4 (6.2) reps to 19.5 (6.4) reps. The 

BODYPUMP group increased from 18.6 (7.0) reps to 23.6 (7.3) reps. Females had higher initial scores 

than the males but the level of improvement was similar with males increasing by 4.3 (6.6) reps and 

females by 5.5 (6.0) reps. These increases were statistically significant. The BODYATTACK group 

recorded slight decreases in muscular endurance. Subjects decreased from 15.9 (2.7) reps to 14.5 (5.4) 

reps, an decrease of 1.4 (4.2) reps. Male subjects started at a lower number of reps than the females and

decreased their number of repetitions. They changed from 14.4 (1.9) to 11.6 (2.4) reps. Females started 

from 18.3(2.1) and increases to 19.3 (5.8) reps. The changes in upper body muscular endurance achieved 

by BODYATTACK males and females were not statistically significant. The BODYCOMBAT group 

increased from 15.9 (6.4) reps to 19.2 (4.2) reps, an increase of 3.3 (8.6) reps. Males from the 

BODYCOMBAT group started at 16.3 (8.4) and increased to 17.3 (4.6) reps. The females started at 15.7 

(6.2) and increased to 20.0 (4.0). Neither the male or female increase in upper body muscular endurance 

was statistically significant. The BODYSTEP group recorded small increases in upper body muscular 

endurance. The group increased from 15.6 (3.1) reps to 16.8 (4.1) reps, the males increased from 15.6 

(3.7) reps to 16.1 (4.4) reps, and the females increased from 15.7 (1.2) reps to 18.7 (3.2) reps. The RPM 

group decreased both as a group and as males and females. The group score decreased from 17.2 (7.4) 

reps to 15.6 (3.6) reps, the males decreased from 13.4 (4.3) to 13.2 (2.9) and the females decreased from 

22.0 (8.1) to 18.5 (1.9). None of these changes were statistically significant. 

Table 13: Change in lower body strength as a result of the intervention 


BODYATTACK 

BODYCOMBAT 

BODYSTEP 

RPM 


Mean (SD) 6RM leg press (kg) 


Group 125.7 (45.0) 141.0 (42.4) 15.9 (24.2) 0.000 

Males 158.4 (39.1) 167.2 (34.3) 9.4 (31.4) 0.265 

Females 103.9 (34.7) 123.6 (38.7) 20.0 (17.9) 0.000 

Group 136.9 (39.0) 164.8 (48.2) 27.9 (26.6) 0.021 

Males 154.0 (16.7) 184.8 (30.7) 30.8 (31.8) 0.096 

Females 108.3 (53.0) 131.3 (59.5) 23.0 (19.9) 0.180 

Group 121.8 (43.6) 149.0 (35.4) 27.2 (19.3) 0.002 

Males 170.0 (34.6) 186.7 (23.1) 16.7 (11.5) 0.130 

Females 101.1 (28.2) 132.9 (26.3) 31.7 (20.9) 0.007 

Group 136.8 (37.2) 158.2 (39.7) 21.4 (25.9) 0.021 

Males 154.4 (25.6) 177.5 (24.9) 23.1 (28.7) 0.056 

Females 90.0 (10.0) 106.7 (15.3) 16.7 (20.8) 0.300 

Group 157.0 (48.8) 186.0 (50.8) 29.0 (16.0 ) 0.000 

Males 196.0 (34.4) 222.0 (49.2) 26.0 (16.7) 0.025 

Females 118.0 (19.2) 150.0 (12.2) 32.0 (16.4) 0.012 

Lower body strength of the whole group as measured using the horizontal leg press, increased from 131.8 

(44.1) kg to 150.4 (41.3) kg. The BODYPUMP group increased from 125.7 (45.0) kg to 141.0 (42.4) kg.

The female BODYPUMP group improved their leg press scores to a greater degree than the males. 

Females improved from 103.9 (34.7) to 123.6 (38.7), an increase of 20.0 (17.9). Males improved from 

158.4(39.1) to 167.2 (34.3), an increase of 9.4 (31.4). Only the increase from the female group was 

statistically significant. The BODYATTACK group increased from 136.9 (39.0) kg to 164.8 (48.2) kg, an 

increase of 27.9 (26.6) kg. Both males and females achieved good increases in the leg press. Females 

improved from 108.3 (53.0) to 131.3 (59.5), an increase of 23.0 (19.9). Males improved from 154.0 (16.7) to 

184.8 (30.7), an increase of 30.8 (31.8). The increases achieved by BODYATTACK males and females 

were not statistically significant. The BODYCOMBAT group increased from 121.8 (43.6) kg to 149.0 

(35.4) kg, an increase of 27.2 (19.3) kg. Females improved from 101.1 (28.2) to 132.9 (26.3), an increase 

of 31.7 (20.9). Males improved from 170.0 (34.6) to 186.7 (23.1), an increase of 16.7 (11.5). Only the 

increase achieved by the females was statistically significant. The BODYSTEP group increased from 

136.8 (37.2) kg to 158.2 (39.7) kg, an increase of 21.4 (25.9) kg. Females improved from 90.0 (10.0) to 

106.7 (15.3), an increase of 16.7 (20.8). Males improved from 154.4 (25.6) to 177.5 (24.9), an increase of 

23.1 (28.7). The increase achieved by the males approached statistical significance. The RPM group 

increased from 157.0(48.8) kg to 186.0(50.8) kg, an increase of 29.0(16.0) kg. Males and females 

improved to a similar degree. . Females improved from 118.0(19.2) to 150.0(12.2), an increase of 32.0 

(16.4). Males improved from 196.0 (34.4) to 222.0 (49.2), an increase of 26.0 (16.7). Both the male or 

female group increases were statistically significant. 

Table 14: Change in lower muscular endurance as a result of the intervention 


BODYATTACK 

BODYCOMBAT 

BODYSTEP 


Mean (SD) number of repetitions of the leg press at 70% of 

6RM 


Group 38.7 (22.4) 43.6 (21.3) 4.3 (9.0) 0.003 

Males 39.6 (27.2) 42.9 (25.7) 3.7 (7.3) 0.085 

Females 38.1 (19.2) 44.0 (18.4) 4.6 (10.0) 0.015 

Group 40.6 (17.5) 42.4 (19.1) 1.8 (7.8) 0.544 

Males 34.4 (9.1) 32.8 (8.8) -1.6 (2.7) 0.256 

Females 51.0 (25.4) 58.3 (22.5) 7.3 (11.0) 0.370 

Group 37.8 (10.2) 45.0 (11.2) 7.2 (11.0) 0.068 

Males 37.0 (3.6) 35.7 (4.0) -1.3 (3.5) 0.578 

Females 38.1 (12.3) 49.0 (11.0) 10.9 (11.2) 0.042 

Group 36.7 (15.4) 42.8 (18.4) 6.1 (10.7) 0.088 

Males 36.4 (16.8) 42.5 (19.5) 6.1 (10.0) 0.128 

Females 37.7 (14.0) 43.7 (18.9) 6.0 (14.8) 0.555

RPM 


Group 36.5 (9.1) 36.7 (12.4) 0.2 (10.7) 0.954 

Males 33.6 (7.4) 34.4 (7.9) 0.8 (2.8) 0.554 

Females 39.4 (10.5) 39.0 (16.4) -0.4 (15.8) 0.958 

For the group as a whole lower body muscular endurance, as measured by the number of repetitions 

performed on the leg press at 70% of 6RM, increased from 38.7 (23.6) reps to 43.2 (13.0) reps. The 

BODYPUMP group increased from 38.7 (22.4) reps to 43.6 (21.3) reps. Females increased from 38.1 

(19.2) reps to 44.0 (18.4) reps, an increase of 4.6 (10.0) reps. Males increased from 39.6 (27.2) reps to 

42.9 (25.7) reps, an increase of 3.7 (7.3) reps. The increase for the female group was statistically 

significant. The BODYATTACK group increased from 40.6 (17.5) reps to 42.4 (19.1) reps, an increase of 

1.8 (7.8) reps. Females increased from 51.0 (25.4) reps to 58.3 (22.5) reps, an increase of 7.3 (11.0) reps. 

Males decreased from 34.4 (9.1) reps to 32.8 (8.8) reps, a decrease of 1.6 (2.7) reps. The changes in lower 

body muscular endurance achieved by BODYATTACK males and females were not statistically 

significant. The BODYCOMBAT group increased from 37.8 (10.2) reps to 45.0 (11.2) reps, an increase of 

7.2 (11.0) reps. Males from the BODYCOMBAT group increased from 37.0 (3.6) to 35.7 (4.0) reps. The 

females increased from 38.1 (12.3) to 49.0 (11.0). Only the female increase in lower body muscular 

endurance was statistically significant. The BODYSTEP group recorded an increase in lower body 

muscular endurance from 36.7 (15.4) to 42.8 (18.4) reps. The males increased from 36.4 (16.8) reps to 

42.5 (19.5) reps, and the females increased from 37.7 (14.0) reps to 43.7 (18.9) reps. None of these 

changes were statistically significant. The RPM group recorded had similar pre and post measures for 

lower body muscular endurance. The group changed from 36.5 (9.1) to 36.7 (12.4) reps. The males 

increased from 33.6 (7.4) reps to 34.4 (7.9) reps, and the females decreased slightly from 39.4 (10.5) reps 

to 39.0 (16.4) reps. None of these changes in the RPM group were statistically significant. 

Psychological state as measured by a 20 point questionnaire improved by 10.7 (9.38) points. This reflected 

a decrease in negative emotions by 2.54 (4.43) points and an increase in positive emotions by 8.15 (9.66) 

points. The BODYPUMP subjects increased by 10.9 (8.2) points, from 16.8 (7.8) to 27.0 (7.4). 

BODYPUMP males increased from 17.0(6.7) to 26.5 (4.6), an increase of 10.7 (8.8) while BODYPUMP 

females increased from 16.6 (8.5) to 27.3 (8.9), a change of 11.0 (8.0). Both the male and female increases 

were statistically significant. BODYATTACK subjects improved from 15.1 (6.4) to 23.0 (8.7). The 

BODYATTACK males increased from 17.6 (5.6) to 25.2 (10.2). The BODYATTACK females increased 

from 11.0 (6.1) to 19.3 (5.0). The female increase was statistically significant. The BODYCOMBAT group 

increased from 7.8 (6.3) to 20.7 (10.4). ). The BODYCOMBAT males increased from 9.7 (3.8) to 21.0 

(2.6). The BODYCOMBAT females increased from 7.0 (7.3) to 20.6 (12.6). Both the male and female 

increases were statistically significant. The BODYSTEP group increased from 17.6 (7.0) to 26.5 (6.1). 

The BODYSTEP males increased from 18.5 (7.7) to 27.3 (7.1). The BODYSTEP females increased 

from 15.3 (5.0) to 24.7 (2.1). Only the BODYSTEP female increase was statistically significant. The 

RPM group increased from 13.0 (13.1) to 21.3 (8.1). The RPM males increased from 16.6 (7.7) to 22.0

(5.2). The RPM females increased from 9.4 (17.1) to 20.6 (10.9). Only the RPM female increase was 

statistically significant. 

Table 15: Change in psychological state as a result of the intervention 


BODYATTACK 

BODYCOMBAT 

BODYSTEP 

RPM 


Mean psychological test score 


Group 16.8 (7.8) 27.0 (7.4) 10.9 (8.2) 0.000 

Males 17.0 (6.7) 26.5 (4.6) 10.7 (8.8) 0.000 

Females 16.6 (8.5) 27.3 (8.9) 11.0 (8.0) 0.000 

Group 15.1 (6.4) 23.0 (8.7) 7.9 (7.8) 0.025 

Males 17.6 (5.6) 25.2 (10.2) 7.6 (10.3) 0.173 

Females 11.0 (6.1) 19.3 (5.0) 8.3 (2.1) 0.020 

Group 7.8 (6.3) 20.7 (10.4) 12.9 (10.1) 0.003 

Males 9.7 (3.8) 21.0 (2.6) 11.3 (1.5) 0.006 

Females 7.0 (7.3) 20.6 (12.6) 13.6 (12.2) 0.026 

Group 17.6 (7.0) 26.5 (6.1) 8.9 (4.2) 0.000 

Males 18.5 (7.7) 27.3 (7.1) 8.8 (4.4) 0.001 

Females 15.3 (5.0) 24.7 (2.1) 9.3 (4.7) 0.076 

Group 13.0 (13.1) 21.3 (8.1) 8.3 (7.5) 0.007 

Males 16.6 (7.7) 22.0 (5.2) 5.4 (5.3) 0.086 

Females 9.4 (17.1) 20.6 (10.9) 11.2 (8.8) 0.047

Table 16: Combined results for BODYPUMP 

Sum of 8 skinfolds 

(mm) 

Beep test level 

6RM Bench Press 

Bench Press 

repetitions at 70% of 

6RM 

6RM Leg Press 

Leg Press 


6RM 

Psychological score 



Group 176.2 (59.4) 145.3 (50.4) 29.9 (22.9) 0.000 

Males 152.3 (47.8) 127.5 (45.3) 23.7 (21.7) 0.000 

Females 192.1 (62.0) 157.1 (51.0) 33.8 (23.2) 0.000 

Group 41.0 (23.4) 46.0 (26.0) 5.1 (6.8) 0.000 

Males 55.3 (23.4) 61.5 (28.5) 6.3 (8.5) 0.009 

Females 31.5 (18.2) 35.7 (18.5) 4.3 (5.6) 0.001 

Group 33.0 (14.8) 38.1 (15.0) 5.2 (5.4) 0.000 

Males 47.0 (11.7) 52.8 (10.9) 6.0 (5.8) 0.001 

Females 23.6 (7.5 ) 28.4 (7.5) 4.7 (5.3) 0.000 

Group 18.6 (7.0) 23.6 (7.3) 5.1 (6.2) 0.000 

Males 14.8 (4.6) 18.9 (5.1) 4.3 (6.6) 0.022 

Females 21.1 (7.2) 26.8 (6.9) 5.5 (6.0) 0.000 

Group 125.7 (45.0) 141.0 (42.4) 15.9 (24.2) 0.000 

Males 158.4 (39.1) 167.2 (34.3) 9.4 (31.4) 0.265 

Females 103.9 (34.7) 123.6 (38.7) 20.0 (17.9) 0.000 

Group 38.7 (22.4) 43.6 (21.3) 4.3 (9.0) 0.003 

Males 39.6 (27.2) 42.9 (25.7) 3.7 (7.3) 0.085 

Females 38.1 (19.2) 44.0 (18.4) 4.6 (10.0) 0.015 

Group 16.8 (7.8) 27.0 (7.4) 10.9 (8.2) 0.000 

Males 17.0 (6.7) 26.5 (4.6) 10.7 (8.8) 0.000 

Females 16.6 (8.5) 27.3 (8.9) 11.0 (8.0) 0.000

Table 17: Combined results for BODYATTACK 


(mm) 



Bench Press 


6RM 

6RM Leg Press 

Leg Press repetitions 

at 70% of 6RM 




Group 198.4 (52.7) 167.5 (49.4) 31.0 (34.6) 0.039 

Males 189.1 (49.5) 178.6 (56.9) 10.6 (12.7) 0.136 

Females 214.0 (65.0) 149.0 (35.4) 65.0 (32.9) 0.048 

Group 44.9 (23.6) 58.3 (26.4) 13.4 (8.1) 0.002 

Males 50.2 (26.9) 64.9 (27.9) 14.4 (9.1) 0.024 

Females 36.0 (17.7) 47.7 (25.0) 11.7 (7.4) 0.111 

Group 36.4 (12.5) 45.8 (19.4) 9.4 (8.6) 0.017 

Males 43.0 (10.8) 54.0 (18.8) 11.0 (8.8) 0.049 

Females 25.3 (4.5) 32.2 (12.7) 6.8 (9.4) 0.340 

Group 15.9 (2.7) 14.5 (5.4) -1.4 (4.2) 0.390 

Males 14.4 (1.9) 11.6 (2.4) -2.8 (3.0) 0.108 

Females 18.3 (2.1) 19.3 (5.8) 1.0 (5.6) 0.790 

Group 121.8 (43.6) 149.0 (35.4) 27.2 (19.3) 0.002 

Males 170.0 (34.6) 186.7 (23.1) 16.7 (11.5) 0.130 

Females 101.1 (28.2) 132.9 (26.3) 31.7 (20.9) 0.007 

Group 40.6 (17.5) 42.4 (19.1) 1.8 (7.8) 0.544 

Males 34.4 (9.1) 32.8 (8.8) -1.6 (2.7) 0.256 

Females 51.0 (25.4) 58.3 (22.5) 7.3 (11.0) 0.370 

Group 15.1 (6.4) 23.0 (8.7) 7.9 (7.8) 0.025 

Males 17.6 (5.6) 25.2 (10.2) 7.6 (10.3) 0.173 

Females 11.0 (6.1) 19.3 (5.0) 8.3 (2.1) 0.020

Table 18: Combined results for BODYCOMBAT 


(mm) 



Bench Press 


6RM 

6RM Leg Press 


at 70% of 6RM 




Group 176.4 (62.0) 153.8 (53.8) 22.6 (23.8) 0.015 

Males 122.5 (61.1) 123.2 (61.0) -0.7 (3.9) 0.794 

Females 199.4 (49.6) 166.9 (49.3) 32.6 (21.5) 0.007 

Group 55.6 (30.6) 66.0 (27.3) 10.4 (8.2) 0.003 

Males 86.7 (30.0) 96.0 (23.6) 9.3 (6.4) 0.128 

Females 42.3 (20.4) 53.1 (16.9) 10.9 (9.3) 0.022 

Group 41.3 (22.4) 46.7 (24.3) 5.4 (10.5) 0.143 

Males 68.3 (17.6) 69.2 (20.1) 0.8 (3.8) 0.742 

Females 29.7 (11.3) 37.0 (19.7) 7.3 (12.1) 0.163 

Group 15.9 (6.4) 19.2 (4.2) 3.3 (8.6) 0.255 

Males 16.3 (8.4) 17.3 (4.6) 1.0 (13.0) 0.906 

Females 15.7 (6.2) 20.0 (4.0) 4.3 (7.1) 0.162 

Group 121.8 (43.6) 149.0 (35.4) 27.2 (19.3) 0.002 

Males 170.0 (34.6) 186.7 (23.1) 16.7 (11.5) 0.130 

Females 101.1 (28.2) 132.9 (26.3) 31.7 (20.9) 0.007 

Group 37.8 (10.2) 45.0 (11.2) 7.2 (11.0) 0.068 

Males 37.0 (3.6) 35.7 (4.0) -1.3 (3.5) 0.578 

Females 38.1 (12.3) 49.0 (11.0) 10.9 (11.2) 0.042 

Group 7.8 (6.3) 20.7 (10.4) 12.9 (10.1) 0.003 

Males 9.7 (3.8) 21.0 (2.6) 11.3 (1.5) 0.006 

Females 7.0 (7.3) 20.6 (12.6) 13.6 (12.2) 0.026

Table 19: Combined results for BODYSTEP 


(mm) 



Bench Press 


6RM 

6RM Leg Press 


at 70% of 6RM 




Group 163.7 (40.8) 154.3 (38.9) 9.4 (26.1) 0.259 

Males 159.9 (40.4) 151.4 (39.9) 8.4 (24.6) 0.365 

Females 174.0 (48.9) 162.0 (43.4) 12.0 (35.5) 0.618 

Group 58.4 (20.8) 72.9 (25.8) 14.5 (10.8) 0.001 

Males 63.4 (21.2) 80.1 (24.1) 16.8 (11.1) 0.004 

Females 45.0 (14.7) 53.7 (23.3) 8.7 (8.7) 0.228 

Group 45.0 (18.8) 50.1 (21.8) 5.1 (5.5) 0.011 

Males 53.8 (13.4) 60.2 (15.4) 6.4 (5.0) 0.008 

Females 21.7 (3.1) 23.3 (8.5) 1.7 (6.3) 0.693 

Group 15.6 (3.1) 16.8 (4.1) 1.2 (4.7) 0.427 

Males 15.6 (3.7) 16.1 (4.4) 0.5 (5.3) 0.797 

Females 15.7 (1.2) 18.7 (3.2) 3.0 (2.6) 0.188 

Group 136.8 (37.2) 158.2 (39.7) 21.4 (25.9) 0.021 

Males 154.4 (25.6) 177.5 (24.9) 23.1 (28.7) 0.056 

Females 90.0 (10.0) 106.7 (15.3) 16.7 (20.8) 0.300 

Group 36.7 (15.4) 42.8 (18.4) 6.1 (10.7) 0.088 

Males 36.4 (16.8) 42.5 (19.5) 6.1 (10.0) 0.128 

Females 37.7 (14.0) 43.7 (18.9) 6.0 (14.8) 0.555 

Group 17.6 (7.0) 26.5 (6.1) 8.9 (4.2) 0.000 

Males 18.5 (7.7) 27.3 (7.1) 8.8 (4.4) 0.001 

Females 15.3 (5.0) 24.7 (2.1) 9.3 (4.7) 0.076

Table 20: Combined results for RPM 


(mm) 



Bench Press repetitions 

at 70% of 6RM 

6RM Leg Press 

Leg Press repetitions at 

70% of 6RM 


Discussion 



Group 189.2 (62.9) 161.5 (58.9) 27.7 (23.3) 0.005 

Males 139.3 (41.2) 127.2 (50.3) 12.1 (16.6) 0.179 

Females 239.0 (31.3) 195.7 (48.4) 43.3 (18.3) 0.006 

Group 50.2 (27.6) 59.5 (30.2) 9.3 (10.2) 0.018 

Males 72.4 (19.0) 84.0 (14.5) 11.6 (11.9) 0.095 

Females 28.0 (11.1) 35.0 (18.6) 7.0 (8.9) 0.154 

Group 43.3 (21.8) 47.5 (22.0) 3.8 (6.0) 0.079 

Males 55.5 (22.4) 59.5 (23.5) 4.0 (6.8) 0.256 

Females 28.1 (6.9) 32.5 (3.5) 3.5 (6.0) 0.271 

Group 17.2 (7.4) 15.6 (3.6) -1.5 (5.9) 0.443 

Males 13.4 (4.3) 13.2 (2.9) -0.2 (2.6) 0.871 

Females 22.0 (8.1) 18.5 (1.9) -2.8 (8.2) 0.504 

Group 157.0 (48.8) 186.0 (50.8) 29.0 (16.0 ) 0.000 

Males 196.0 (34.4) 222.0 (49.2) 26.0 (16.7) 0.025 

Females 118.0 (19.2) 150.0 (12.2) 32.0 (16.4) 0.012 

Group 36.5 (9.1) 36.7 (12.4) 0.2 (10.7) 0.954 

Males 33.6 (7.4) 34.4 (7.9) 0.8 (2.8) 0.554 

Females 39.4 (10.5) 39.0 (16.4) -0.4 (15.8) 0.958 

Group 13.0 (13.1) 21.3 (8.1) 8.3 (7.5) 0.007 

Males 16.6 (7.7) 22.0 (5.2) 5.4 (5.3) 0.086 

Females 9.4 (17.1) 20.6 (10.9) 11.2 (8.8) 0.047 

The purpose of this study was to quantify the physical and psychological response to 13 weeks of group 

exercise classes in previously sedentary adults. Subjects performed a battery of fitness tests immediately 

prior to and immediately following the 13-week intervention. The intervention consisted of participation in 

LES MILLS Body Training Systems aerobics classes, specifically; BODYPUMP, BODYATTACK, 

BODYSTEP, BODYCOMBAT and RPM. Seventy-nine subjects finished the 13 weeks and satisfied 

the criteria for inclusion in the study. The distribution of subjects is shown below (Refer to Table 21).

Table 21: Distribution of subjects who finished the study 


Group Males Females 

BODYPUMP 40 16 24 

BODYATTACK 8 5 3 

BODYCOMBAT 10 3 7 

BODYSTEP 11 8 3 

RPM 10 5 5 

Body Composition 

TOTAL 79 37 42 

A strategy to modify body composition typically involves both dietary modification and an exercise 

intervention. This study used only an exercise intervention. The average decrease in percent body fat of all 

the subjects was 2.1% (a decrease in skinfolds of 21mm). The subjects who performed BODYPUMP had 

the largest decrease in percent body fat (2.7%) with similar decreases for the men and women in the 

group. This is despite a lower caloric demand of the BODYPUMP class in comparison to 

BODYATTACK, BODYSTEP, BODYCOMBAT and RPM (Refer to Table 22). 

Table 22: Caloric demand of Les Mills Body Training System (LMBTS) classes 

BODYSTEP 

Average (SD) 

Class 

Duration 

(mins) 

Total Calories used in 

class 

Cal per min of 

class 

[1, 7] 

Total Cal per 75 kg 

of bodyweight 

54.5 555.6 (64.8) 10.2 (1.1) 575.6 (95.6) 

BODYATTACK 

Average (SD) 57.0 631.0 (103.2) 11.1 (1.8) 700.0 (64.7) 

BODYCOMBAT 

Average (SD) 44.7 462.8 (82.2) 10.4 (1.8) 509.8 (44.0) 

RPM 

Average (SD) 


Average (SD) 

45.3 582.1 (92.8) 12.8 (1.9) 636.6 (56.1) 

57.0 411.0 (99.3) 7.2 (1.6) 433.6 (99.3) 

The fact that the BODYPUMP subjects had the largest reduction in body fat despite a lower acute caloric 

expenditure, suggests that resting metabolic rate was increased as a result of the muscular activity of the 

class. This would have the effect of increasing daily caloric expenditure and may help explain the decrease 

in body fat reported. The size of the sample and the high level of statistical significance strengthen the 

merits of this suggestion. The female subjects in the RPM group also recorded a large decrease in

percent body fat (3.3%). This group, however, started from a level of body fat that was substantially higher 

than the males in the RPM group and the females in other groups. This higher level of body fat 

moderates the larger reduction over the 13 weeks. The males in the BODYCOMBAT group had a similar 

situation, reporting no reduction in body fat over the 13 weeks. Closer inspection of this result shows that 

there were only three subjects and that they were initially very lean (they had the lowest level of body fat of 

any group at the commencement of the study). The reductions in body fat for all subjects were reasonably 

consistent. The addition of a controlled caloric intake would most likely result in greater reductions in body 

fat. 

Aerobic Fitness 

The multi-stage fitness test (beep test) is a very simple way to measure aerobic fitness. It provides the ideal 

test to assess the fitness of large groups of people such as the sample used in this study. The table in 

appendix 2 shows the approximation to VO2 max from each level in the beep test (please refer to 

Appendix). The BODYPUMP group had small increases in their beep test scores which reflects the 

nature of the class. ie it has a muscular focus as opposed to an aerobic focus. All the other classes had 

more sizeable increases in their beep test scores. BODYATTACK and BODYSTEP had the largest 

increases in beep test score, which reflects their aerobic focus. This is supported by a previous study 

performed by the same author reported high aerobic intensities for these classes [1] 

. The beep test is not 

without criticism as a measure of aerobic fitness. It requires the ability to run and change direction every 

20m. It is possible that some subjects were unable to perform this test to the best of their ability because of 

their perceived inability to run and change direction quickly. This was illustrated by some subjects recording 

the same or a lower result on the second test (after 13 weeks of exercise). Had an alternative test been 

used to measure aerobic fitness the improvements achieved may have been higher. 

Upper Body Strength 

The bench press is one of the most fundamental strength training exercises. Its movements closely 

resemble the basic pushup, which is likely to have been performed by every person at some stage of their 

life. Performing the bench press using free weights (a barbell and weights) is more challenging than using a 

machine as it requires a degree of balance and coordination. To overcome this technical prerequisite, all 

subjects were given basic instruction in the exercise prior to performing the test. All groups reported 

improvements in their 6RM bench press ranging from 3.8 to 9.4 kg. Some of the classes do not specifically 

address upper body strength and as a consequence were unlikely to result in anything more than small 

changes in upper body strength. However, other classes, such as BODYPUMP, do provide a 

comprehensive upper body muscular workout. The modest increases in upper body strength in the 

BODYPUMP group suggest that the training variables of the class (repetitions, load, rests etc) do not 

specifically promote an increase in 6RM strength. [8] 


Upper Body Muscular Endurance 

Upper body muscular endurance was assessed with the subjects performing as many repetitions as 

possible of the bench press using 70% of their 6RM load. The load that was used for the muscle endurance 

test was not the same for both tests. Consequently, if a subject’s 6RM load increased from test 1 to test 2 

so did their muscle endurance load. As a result of this there were some decreases in muscle endurance 

shown (by the BODYATTACK group and the RPM group). The BODYPUMP group demonstrated 

the largest change in upper body muscular endurance with an average increase of 5.1 repetitions or 

27.5%. This indicates that the training variables of the class do specifically promote an increase in upper 

body muscular endurance. Motivation is a key component in this particular test. Some subjects reported 

that despite feeling stronger and in better condition than at the start of the study, they were unable to 

perform as many repetitions as the first test due to a lack of motivation and concentration. 

Lower Body Strength 

Lower body strength was measured using a pin-loaded horizontal leg press. The subject’s 6RM was 

measured. All groups reported increases on this test with an average increase of 18.6 kg. All classes 

involve considerable lower body activity. BODYPUMP involves specific strength training exercises such 

as weighted Squats and Lunges. BODYSTEP incorporates bench-stepping movements and RPM uses 

slower cadences and a higher fly-wheel resistance to promote strength increases. BODYATTACK and 

BODYCOMBAT do not use a specific tool or apparatus but incorporate large amounts of lower body 

calisthenic movements. The high level of statistical significance for most of the groups suggests that 

regardless of the class chosen, a novice participant undertaking a Les Mills International franchised 

program will receive an improvement in lower body strength. 

Lower Body Muscular Endurance 

Lower body muscular endurance was assessed with the subjects performing as many repetitions as 

possible of the leg press using 70% of their 6RM load. In contrast to the large increase in leg press 6RM 

strength, the increases in lower body muscular endurance were relatively modest. Because the 6RM 

scores increased significantly, the loads used for the muscle endurance test also increased significantly. 

This offers some explanation for the lower scores. For all subjects the number of repetitions performed 

before failure still increased by 4.5 repetitions, representing a 12% increase in muscular endurance. 

However, in contrast to the 6RM leg press results, the level of statistical significance was not high enough 

to conclusively indicate an effect. 

Psychological Well-being 

Questionnaires are the common method of non-clinical psychological assessment. The questionnaire used 

in this study was selected because it contained a balanced assessment of both positive and negative 

emotions and consequently documented improvements in positive emotions as well as the typical decrease 

in negative emotions as a result of an exercise program. The result was a clear and significant increase in 


the psychological well-being of the subjects. The positive emotions changed to a larger degree than the 

negative emotions. Indeed, the 10.7-point change in the emotional index was made up from a 2.5 point 

reduction in negative emotions and an 8.2 increase in positive emotions. Subjects reported marked 

improvements in emotional strength, and feelings of alertness and pride. They also felt more inspired and 

active. 

Subject Adherence 

Dropout rate is always a major concern of studies involving untrained subjects in an exercise program. The 

dropout rate in this study was 47.3% which is lower than typically expected for a study such as this. This 

suggests that the nature of the program improved the rate of retention of subjects. 

Limitations 

The level of adaptation that occurs in response to a stimulus is dependent largely on the intensity of that 

stimulus. As the subjects did not have the intensity of their sessions monitored, there was no way of 

determining whether the individual intensities selected were sufficient to result in any significant adaptation. 

During the fitness testing sessions it became apparent that some subjects were prepared to exert 

themselves maximally and work at a high intensity while others were not so willing. A study that ensured an 

appropriate and consistent intensity during both testing and exercise sessions would be likely to 

demonstrate significantly larger increases in physical fitness than those reported in this study. 

The sample size in some of the groups did not allow for statistical significance to be reached. This was 

particularly reflected when males and females were considered separately. BODYSTEP females, 

BODYATTACK females and BODYCOMBAT males only had three subjects in the group. Greater 

numbers in these groups would have provided a greater insight into their longitudinal effect on untrained 

subjects. 

Conclusion 

The results of this study show that untrained subjects can achieve significant improvements in physical 

fitness and psychological well-being through participation in 13 weeks of BODYPUMP, 

BODYATTACK, BODYSTEP, BODYCOMBAT or RPM group exercise sessions. As the exercise 

variables are different between the classes, so too are the specific adaptations received after long term 

participation but there are nonetheless general positive changes in body composition, aerobic fitness, 

upper and lower body strength and muscular endurance and psychological well-being. The lack of a 

prescribed and monitored exercise intensity may have resulted in improvements in fitness and 

psychological well-being that did not accurately reflect the demands of each of the classes which as 

determined in a previous study was substantial. Further research should attempt to control exercise 

intensity and should also ensure that sufficient numbers of subjects are present in all groups. 


eferences 

1. Lythe J and Pfitzinger P. (1999). Caloric expenditure and aerobic demand of BODYSTEP, 

BODYATTACK, BODYCOMBAT and RPM. Auckland: UniSports, University of Auckland:15. 

2. Durnin J V and Womersley J.(1974). Body fat assessed from total body density and its estimation 

from skinfold thickness: measurements on 481 men and women aged 16 to 72 years. British Journal of 

Nutrition; 32:77-97. 

3. Siri W E. (1961). Body composition from fluid spaces and density: analysis of methods. In: Brozek 

J and Henschel A, eds. Techniques for Measuring Body Composition. Washington DC: National Academy 

of Sciences: 223-244. 

4. Heyward V H. (1996). Evaluation of body composition. Sports Medicine;22(3): 146-156. 

5. Knutzen K M, Brilla L R and Caine D. (1999). Validity of 1RM prediction equations for older adults. 

Journal of Strength and Conditioning Research; 13(3):242-246. 

6. Abadie B R, Altorfer G L and Schuler P B. (1999). Does a regression equation to predict maximum 

strength in untrained lifters remain valid when the subjects are technique trained? Journal of Strength and 

Conditioning Research; 13(3):259-263. 

7. Stanforth D, Stanforth P and Hoemeke M. (2000). Physiologic and metabolic responses to a 

BODYPUMP workout. Journal of Strength and Conditioning Research; 14(2):144-150. 

8. Tan B. (1999). Manipulating resistance-training program variables to optimize maximum strength in 

men: A review. Journal of Strength and Conditioning Research; 13(3):289-304. 


Appendix A 

Table 23: Relationship of Repetitions to 1RM 

Repetitions Percentage of 1RM 

1 100.0 

2 93.5 

3 91.0 

4 88.5 

5 86.0 

6 83.5 

7 81.0 

8 78.5 

9 76.0 

10 73.5 


Appendix b 

PSYCHOLOGICAL QUESTIONNAIRE 

PANAS – Form WC1 

NAME_____________________________________________________________________ 

SIGNED_______________________________________________DATE_______________ 

INSTRUCTIONS: 

Below is a list of words that describe feelings people have. We are interested in how participation in 

Les Mills’ group exercise classes affects your positive and negative mood states. Please read each word 

and then CIRCLE THE NUMBER THAT BEST DESCRIBES HOW YOU HAVE FELT IN THE LAST 

WEEK. 

Not at all A little Moderately Quite a bit Extremely 


(0) (1) (2) (3) (4) 

Interested 0 1 2 3 4 

Distressed 0 1 2 3 4 

Excited 0 1 2 3 4 

Upset 0 1 2 3 4 

Strong 0 1 2 3 4 

Guilty 0 1 2 3 4 

Scared 0 1 2 3 4 

Hostile 0 1 2 3 4 

Enthusiastic 0 1 2 3 4 

Proud 0 1 2 3 4 

Irritable 0 1 2 3 4 

Alert 0 1 2 3 4 

Ashamed 0 1 2 3 4 

Inspired 0 1 2 3 4 

Nervous 0 1 2 3 4 

Determined 0 1 2 3 4 

Attentive 0 1 2 3 4 

Jittery 0 1 2 3 4 

Active 0 1 2 3 4 

Afraid 0 1 2 3 4 

Thank you for completing this form

Appendix c 

Table 24: Relationship of beep test score to VO2 max 

Beep 

Level 

VO2 max Beep 

Level 

VO2 max Beep 

Level 


VO2 max Beep Level VO2 max 

24 26.4 54 37.4 84 47.1 114 56.0 

25 26.8 55 37.8 85 47.4 115 56.2 

26 27.2 56 38.1 86 47.7 116 56.5 

27 27.6 57 38.5 87 48.0 117 56.8 

28 27.9 58 38.8 88 48.3 118 57.1 

29 28.3 59 39.2 89 48.7 119 57.3 

30 28.7 60 39.5 90 49.0 120 57.6 

31 29.1 61 39.9 91 49.3 

32 29.5 62 40.2 92 49.6 

33 29.8 63 40.5 93 49.9 

34 30.2 64 40.8 94 50.2 

35 30.6 65 41.1 95 50.5 

36 31.0 66 41.4 96 50.8 

37 31.4 67 41.8 97 51.1 

38 31.8 68 42.1 98 51.4 

39 32.2 69 42.4 99 51.7 

40 32.6 70 42.7 100 51.9 

41 32.9 71 43.0 101 52.2 

42 33.3 72 43.3 102 52.5 

43 33.6 73 43.6 103 52.8 

44 33.9 74 43.9 104 53.1 

45 34.3 75 44.2 105 53.4 

46 34.6 76 44.5 106 53.7 

47 35.0 77 44.8 107 54.0 

48 35.3 78 45.2 108 54.3 

49 35.7 79 45.5 109 54.5 

50 36.0 80 45.8 110 54.8 

51 36.4 81 46.1 111 55.1 

52 36.7 82 46.4 112 55.4 

53 37.1 83 46.8 113 55.7

THE PHYSICAL AND PSYCHOLOGICAL 

RESPONSE TO 18 WEEKS OF 

BODYPUMP IN UNTRAINED 

INDIVIDUALS 

LYTHE J, PFITZINGER, P & HO D. 


INTRODUCTION 

At the conclusion of the 13-week exercise program discussed in the above report, a group of subjects 

performing the BODYPUMP class were asked to continue for a further five weeks. The primary purpose 

of this five-week extension was to investigate the relative physical and psychological changes occurring in 

the first 13 weeks compared to the following five weeks, particularly in body composition. 

METHODS 

Fifteen subjects were asked to perform the extra five weeks. The same class frequency conditions applied 

as during the first 13 weeks, ie to complete between two and five sessions per week. Subjects were then 

tested in an identical manner to the week 1 and week 14 tests. All subjects were tested within seven days 

of finishing their final week of exercise. 

RESULTS 

Eleven (6 males, 5 females) subjects completed the extra five weeks and were fitness tested. The results 

for all tests are shown in below (Table 1). 


Table 1: Results for BODYPUMP subjects for all tests performed at weeks 1, 14 and 19. 

Test 

Parameter 

Beep Test 

Skinfolds 

(mm) 

Percent Body 

fat 

6RM Bench 

Press 

Upper Body 

Muscular 

Endurance 

6RM Leg 

Press 

Lower Body 

Muscular 

Endurance 

Psychological 

Score 

Group Test 1 Test 2 Test 3 


T-test 

1-2* 

T-test 

1-3* 

T-test 

2-3* 

All Subjects 37.7 (14.9) 39.9 (19.1) 42.3 (21.4) 0.33 0.11 0.36 

Males 46.8 (12.1) 49.3 (19.2) 52.7 (22.5) 0.50 0.28 0.42 

Females 26.8 (10.0) 28.6 (12.7) 29.8 (12.5) 0.53 0.11 0.74 

All Subjects 185.9 (45.5) 156.1(35.3) 161.8 (44.0) 0.00 0.00 0.25 

Males 171.7 (40.0) 156.6 (27.3) 152.8 (34.7) 0.07 0.01 0.5 

Females 202.9 (50.2) 155.5 (46.7) 162.7 (55.4) 0.00 0.01 0.02 

All Subjects 32.8 (4.1) 30.1 (4.9) 30.6 (5.4) 0.01 0.01 0.39 

Males 30.4 (3.3) 27.8 (3.0) 27.5 (3.9) 0.07 0.03 0.74 

Females 35.8 (3.0) 32.9 (5.5) 33.4 (4.7) 0.07 0.16 0.04 

All Subjects 35.2 (15.2) 41.5 (16.0) 44.8 (16.9) 0.00 0.00 0.05 

Males 47.1 (8.6) 54.4 (7.7) 58.3 (7.0) 0.01 0.01 0.11 

Females 21.0 (4.6) 25.9 (3.5) 28.5 (6.8) 0.03 0.00 0.32 

All Subjects 19.1 (6.6) 23.0 (7.8) 20.0 (4.6) 0.06 0.61 0.19 

Males 15.7 (5.3) 19.7 (6.0) 17.8 (4.3) 0.21 0.35 0.43 

Females 23.2 (5.9) 27.0 (8.4) 22.6 (3.9) 0.24 0.85 0.35 

All Subjects 131.7 (56.1) 150.4 (46.9) 165.5 (66.9) 0.04 0.02 0.09 

Males 166.5 (48.2) 185.0 (25.1) 208.3 (52.6) 0.26 0.11 0.13 

Females 90.0 (31.4) 108.8 (27.5) 114.0 (40.8) 0.03 0.06 0.51 

All Subjects 45.0 (30.8) 49.2 (28.0) 30.3 (7.9) 0.11 0.19 0.08 

Males 37.5 (34.3) 42.2 (29.6) 28.7 (7.8) 0.13 0.62 0.40 

Females 54.0 (26.7) 57.6 (26.5) 32.2 (8.3) 0.47 0.17 0.12 

All Subjects 17.2 (6.7) 26.4 (5.6) 26.1 (5.0) 0.00 0.00 0.81 

Males 19.3 (7.2) 26.3 (2.8) 26.3 (2.9) 0.04 0.03 1.00 

Females 14.6 (5.7) 26.4 (8.3) 25.8 (7.2) 0.04 0.07 0.79 

*T-test 1-2 indicates statistical significance from test 1 to test 2 

*T-test 1-3 indicates statistical significance from test 1 to test 3 

*T-test 2-3 indicates statistical significance from test 2 to test 3

Discussion 

The beep test score improved from week 1 to week 14 and again to week 19. This trend was shown when 

the group was considered as a whole and when males and females were considered separately. However 

these changes had low statistical significance. The rate of improvement in the beep test was not consistent, 

the males increased at a greater rate from week 14 to week 19 than they did from week 1 to week 14; 

whereas the females had a linear increase (similar per-week improvements in both periods). 

Body fatness showed a considerable and significant decrease from week 1 to week 14 but little or no 

decrease from week 14 to week 19. Both sum of eight skinfolds and percent body fat displayed this trend. 

This suggests that the either the extra five weeks of BODYPUMP did not create a daily caloric deficit 

sufficient to decrease body fatness or that the effects of the extra five weeks have not yet materialized. 

The values for 6RM bench press increased from week 1 to week 14 and continued to increase from week 

14 to week 19. All groups displayed this result (total subjects, males only, females only). The improvements 

were relatively linear in that the increases attributable to the extra five weeks were approximately half the 

increases attributable the first 13 weeks (similar per-week increase as shown in Figure 2). The results for 

upper body muscular endurance decreased. A similar effect was seen for subjects performing the other 

classes over the 13 weeks. This may be due to the fact that motivation was not as great as it was during 

the first tests and that a small sample size did not accurately reflect the effects of the class. 

Leg strength improved from week 1 to week 14 and continued to increase from week 14 to week 19. 

Females showed a decreased rate of improvement in the second block of five weeks as compared to the 

first block of 13 weeks while the males improved at a greater rate during second block of five weeks. The 

increases from week 14 to week 19 were not statistically significant. Lower body muscular endurance 

increased from week 1 to week 14 but decreased for all groups from week 14 to week 19. This result is 

similar to upper body muscular endurance and may reflect a lower level of motivation and a higher absolute 

load being used for the muscular endurance test. 

Psychological score increased from week 1 to week 14 but remained relatively constant between weeks 14 

and 19. This indicates that the improvements in psychological and emotional wellbeing had been achieved 

in the first 13 weeks of exercise and that this improved state of mental health was maintained through 

continued participation. 

CONCLUSIONS 

The purpose of extending the 13-week study for an extra five weeks was to identify the relative changes 

occurring in physical and psychological parameters in the first block of exercise (13 weeks) vs the second 

block of exercise (five weeks). The results indicate that 6RM strength continued to improve in both the 

bench press and the leg press exercise. Beep test scores also continued to improve. All other test 


parameters (body fatness, upper body muscular endurance, lower-body muscular endurance, and 

psychological state) either remained the same or decreased. 

As the sample size was relatively small for the final five weeks of the study there was moderate to low 

statistical significance for the changes that occurred between week 14 and week 19. Future research would 

benefit from a greater sample size. 


EXCESS POST-EXERCISE OXYGEN 

CONSUMPTION FOLLOWING 

BODYPUMP TM 

LYTHE J 


INTRODUCTION 

Maintaining the appropriate balance between caloric intake and caloric expenditure for the purposes of 

weight maintenance or weight loss requires accurate information regarding caloric composition of food that 

is eaten and the caloric cost of daily activities. Exercise sessions are used as an effective means of 

increasing caloric expenditure. The caloric cost of exercise can be determined by directly measuring (or 

estimating) energy expenditure during the exercise session. In addition to the calories that are expended 

during the session, there are additional calories expended during the post-exercise period that are directly 

attributable to the exercise. These additional calories used to be referred to as the oxygen debt but are now 

known as the excess post-exercise oxygen consumption (EPOC) and are consumed by the body to assist 

with the various processes involved with recovery. Excess post exercise oxygen consumption (EPOC) is 


defined as the energy expended in addition to the normal resting metabolic rate as a result of performing 

an exercise session. [24] 

EPOC 

Although the physiological processes that contribute to EPOC have not been clearly defined, potential 

factors affecting post-exercise recovery include elevated body temperature, phosphogen resynthesis, re- 

synthesis of glycogen from lactate, re-saturation of tissue water, re-saturation of venous blood, re- 

saturation of blood in skeletal muscle, re-saturation of myoglobin, redistribution of ions within tissue 

compartments, tissue repair, residual effects of hormones and substrate recycling [5,6] . 

To quantify EPOC it is first necessary to determine a person’s resting metabolic rate (RMR). This is defined 

as the amount of calories consumed and oxygen used by an individual per minute when at rest. It can only 

be measured after an overnight fast of approximately 12 hours (to avoid the thermic effect of a meal) and 

when the subject has refrained from strenuous exercise for approximately 24 hours. RMR is the energy 

required to sustain essential body processes such as respiration, brain function and cardiac function. 

A typical bout of aerobic exercise results in a metabolic elevation that lasts approximately 30 minutes. 

Although more prolonged (three hours) or high-intensity (above the anaerobic threshold) activities may 

cause a greater increase in caloric expenditure, previous studies suggest that intensity of training may have 

a somewhat greater effect upon recovery energy expenditure than duration [5,6] . Weight training is a 

commonly used form of high-intensity anaerobic training among athletes and the general public. Studies of 

weight training indicate that hormonal perturbations, particularly for catecholamin, cortisol and growth 

hormone, can be substantial. This is especially the case if repetitions per set are high (10-12) and the rest 

periods between sets are short (30-60 seconds) [5] . 

Previous research has measured EPOC following a number of different exercise sessions. A review of 

these studies is presented below (Table 1). 

Table 1: Summary of EPOC studies 

Reference Activity EPOC 

Almuzaini (1998) 

Burleson (1998) 

Gore (1990) 

30 minutes of continuous cycling vs 2 x 

15 minutes of cycling with 6 hours in 

between sessions 

27 minutes of treadmill running vs 16 

sets of weight-training exercises 

performed in a circuit fashion 

Treadmill running for 20, 50 and 80 

minutes at 50% and 70% of VO2 max 


2 x 15 minutes = 37.5 kcal 

1 x 30 minutes = 26.7 kcal 

Running = 64 kcal 

Weight training = 95kcal 

50% VO2 max/20 mins = 16 kcal 

50% VO2 max/50 mins = 27kcal 



70% VO2 max/50 mins = 50kcal

Elliot (1992) 

Haltom(1999) 

40 minutes of cycling at 70% maximum 

heart rate vs circuit training (8 

exercises, 4 sets of 15 reps at 50% 

1RM with 30 seconds, rest between 

sets) and resistance training (8 

exercises for 3 sets of 3-8 reps at 90% 

of 1RM with 90 seconds, rest between 

sets) 

Circuit training using 2 sets of 8 

exercises. 20 reps at 75% of 20RM 

load. Rest intervals were either 20 

seconds or 60 seconds 



Cycling = 32 ± 16 

Circuit = 48 ± 20 

Heavy lifting = 51 ± 31 

20seconds = 51.5kcal 

60seconds = 37kcal 

Imamura (1999) 70 minutes of standard Karate training 9.3± 7.7kcal 

Melby, C L (1992) 

Murphy (1992) 

Quinn (1994) 

Sedlock (1991) 



Short (1996) 

Ziegenfuss (1992) 

42 minutes of weight training. 14 sets 

at 12 RM with 60-90 seconds, rest 

between sets 

Set-rest and circuit-style resistance 

training using the same 6 large muscle 

group exercises 

Treadmill walking of 20, 40 and 60 

minutes at 70% of VO2 max 

20 minutes of exercise on cycle vs arm 

crank ergometer at 60% of modespecific 

VO2 max 

30 minutes of treadmill or cycle at 60- 

65% of mode-specific VO2 max 

30 minutes of cycling at 60% of VO2 

peak 

Arm ergometry at high (70% VO2 peak 

for 15 minutes) and low intensity (35% 

VO2 peak for 30 minutes) 

Intermittent cycling (2 minutes at 45% 

VO2 max: 2 minutes at 90% VO2 max) 

and continuous cycling (47 minutes) 

19 kcal 

Circuit training = 24.9 kcal 

Set-Rest = 13.5 kcal 

20 minutes = 46.3 kcal 



Arm = 9.2 kcal 

Cycle = 10.4 kcal 

Cycling = 15 kcal 

Treadmill = 17 kcal 

Women = 9.4 ± 4.7 kcal 

Men = 13 ± 4.6 kcal 

High intensity = 7.8 kcal 

Low intensity = 3.0 kcal 

38 ± 7 kcal for intermittent activity 

27 ± 10 for continuous activity


BODYPUMP is a group-exercise aerobics program that is part of the LES MILLS Body Training 

Systems package. BODYPUMP is designed to provide a full-body workout to improve body composition 

and increase muscular endurance. The class consists of 10 tracks (including a designated warmup and 

cool down) of four to six minutes each, targeting specific body parts. Each track consists of a variety of 

exercises and variations that overload a specific muscle or muscle group. Various published and 

unpublished research has previously been conducted on BODYPUMP. Pfitzinger et al (1999) measured 

aerobic intensity and caloric consumption during BODYPUMP in 12 experienced (6 male and 6 female) 

subjects. A similar study was conducted by Stanforth et al. (2000). This study used 30 inexperienced (15 

male and 15 female) subjects. A comparison between the two studies is presented in Table 2below 

Table 2: The aerobic demand of BODYPUMP 

Variable Stanforth Pfitzinger et al (1999) 

Average VO2 (ml/kg/min) 14.8 ± 1.3 20.2 ± 3.6 

Average % of VO2 max/peak 29.1 ± 3.4 40.7 ± 5.3 

Average Heart Rate (bpm) 123.6 ± 18.7 135.4 ± 12.8 

Average % of HR max 63.0 ± 8.7 74.2 ± 4.7 

Total Calorie Consumption (kcal) 265 ± 60 411.0 ± 99.3 

The differences in caloric consumption and aerobic demand between the two studies may be explained by 

the fact that subjects used by Stanforth had higher levels of aerobic fitness and used significantly lower 

loads during the BODYPUMP class. 

Lythe et al. (2000) measured the change in physical and psychological fitness in 40 previously sedentary 

adults over 13 weeks of BODYPUMP at a frequency of three sessions per week. A summary of results is 

presented in Table 2 below. 

As yet, no study has investigated the EPOC associated with BODYPUMP. The purpose of this study was 

to measure the excess post-exercise oxygen consumption in 12 male subjects following a BODYPUMP 

session. Additional information would be gained about heart rates and typical loading used by experienced 

participants during BODYPUMP 


Table 3: Response to 13 weeks of BODYPUMP in untrained individuals 

Variable Increase/Decrease Change 

Sum of 8 skinfolds (mm) Decrease 29.9 (22.9)* 

Body Fat (%) Decrease 2.7 (2.0)* 

Multi stage Fitness Test Level Increase 5.1 (6.8)* 

6RM Bench Press Increase 5.2 (5.4)* 

Upper Body Muscular Endurance (repetitions 

of a bench press at 70% 6RM) 


Increase 5.1 (6.2)* 

6RM Leg Press Increase 15.9 (24.2)* 

Lower Body Muscular Endurance (repetitions 

of a bench press at 70% 6RM) 

Increase 4.3 (9.0)* 

Psychological Wellness Increase 10.7 (8.8)* 

* Indicates statistical significance at 0.05 level 

METHODS 

Subjects 

Twelve male subjects volunteered to participate in the study. Their physical characteristics are presented 

below (In Table 4). Five subjects were very experienced with BODYPUMP, being either instructors or 

regular participants, while seven subjects, although physically fit and active, were not regular participants of 

BODYPUMP. All subjects provided written consent to participate in the study. 

Table 4: Subject characteristics 

Variable Mean (SD) 

Age (years) 31.9 (4.9) 

Weight (kg) 80.8 (5.6) 

Height (cm) 176.7 (4.8) 

Subjects were required to attend two testing sessions, one for determination of body composition and 

maximal oxygen consumption and the second for performance of BODYPUMP and measurement of 

RMR and EPOC. 

Body Composition 

A body composition assessment was conducted because previous research had identified that resting 

metabolic rate correlates most closely with fat-free body mass. 6] The subject was weighed wearing minimal 

clothing to the nearest 0.1 kg using Seca Alpha digital scales. Height was measured to the nearest 0.1 cm 

using a stadiometer. Skinfold measurements were taken in accordance with ISAK (International Society for 

the Advancement of Kinanthropometry) procedures. Surface markings were made from anatomical 

landmarks and skinfold thicknesses were taken in duplicate using Harpenden calipers from the following

sites, triceps, subscapular, biceps, iliac crest, supraspinale, abdominal, front thigh and medial calf. The two 

measurements taken at each site were averaged to give a value for that site. If the two values differed by 

more than 2mm, a third measurement was taken and the median of the three measures was used as the 

value for that site. 

Percent Body Fat Calculation 

A number of formulae exist to estimate percent body fat from skinfold and other anthropometric 

measurements. Some of these formulae are age, gender and population specific while others are very 

general. The formula used to generate body density for this study was that of Withers et al (1987). This 

equation uses seven sites and was developed on a specific population (athletic males aged 18-37) and 

was considered appropriate for this group of subjects. Percent body fat was then calculated using the 

average of formulae of Siri and Brozek (1961). 

VO2 max 

Body Density = 1.0988 – 0.0004 (sum of triceps, sub-scapular, biceps, supraspinale, abdominal, 

thigh and calf). 

Percent Body Fat = average of: 

((4.95/Body Density)-4.50)*100; and 

((4.57/Body Density)-4.142)*100 

Maximal oxygen consumption was measured during a graded exercise test on a treadmill. Subjects were 

familiarized to the Powerjog treadmill during a 5-10 minute warmup period. During this time the speed of 

the treadmill was varied in an effort to find a speed at which the subject was comfortable running. For all 

subjects this fell between 10 km/h and 13 km/h. After this warmup period the subject was allowed to leave 

the treadmill and perform self-selected stretching exercises. When ready, the subject returned to the 

treadmill. They were fitted with a Polar Accurex heart rate monitor (chest strap and receiver) with the 

receiver set to record heart rate every five seconds. Subjects were also fitted with a mask system to allow 

for the collection of expired gasses. The subjects breathed through a Hans Rudolph mouthpiece connected 

to a Hans Rudolph, two-way, non-rebreathing valve (Kansas City, MO), and wore a nose clip. Inspired air 

was measured using a K520 flow transducer (KL Engineering, Sylmar, CA). Expired gases were 

continuously sampled and averaged every 30 seconds from a 5-liter mixing chamber and analyzed using 

Ametek S-3 A1 oxygen and CD-3A carbon dioxide analysers. Prior to each test, the oxygen and CO2 

analyzers were calibrated using a gas mixture of known concentration. The analyzers and flow transducer 

were interfaced through an 8-bit A/D converter to an IBM-compatible computer. Ventilation, oxygen 

consumption, CO2 production, and respiratory exchange ratio were calculated and displayed using Ametek 

OCM-2 Oxygen Uptake System software. 


The VO2 max test was a continuous, step protocol. The speed of the treadmill was held constant with the 

gradient of the treadmill increasing 1% per minute. Subjects continued until volitional exhaustion. To 

represent VO2 max, all subjects achieved the following criteria: 1) attainment of a heart rate within 10 beats 

per minute of age-predicted maximum (using the equation 220 minus age in years); 2) a plateau in oxygen 

uptake despite an increase in work-rate, and 3) a respiratory exchange ratio of 1.10 or greater. If two of the 

three criteria were met then the highest (30-second average) VO2 recorded was taken as the subjects VO2 

max. Subjects who failed to meet two of these criteria were re-tested within three to five days. Maximal 

heart rate was downloaded from the Polar receiver. Within two minutes of completion of the test a blood 

sample was taken from the fingertip and analyzed for levels of blood lactate using a YSI 1500 sport lactate 

analyzer. 

EPOC Session 

Resting Metabolic Rate 

Subjects arrived at the laboratory at 6:30am after a 12-hour fast and having refrained from strenuous 

exercise for at least 24 hours. Subjects underwent 45 minutes of seated rest in a comfortable environment. 

Gas analysis was used (with the same procedures as during the VO2 max test) during the last 15 minutes 

of this period for determination of resting metabolic rate. Heart rates were also collected every 60 seconds 

during this period and a blood lactate sample was taken from the fingertip at the conclusion of the 45 

minutes. Oxygen consumption values were converted to energy equivalents ranging from 4.851-5.189 kcal 

per liter of oxygen using the updated non-protein calculations of Peronnet and Massicotte (1991). 


Subjects then performed a BODYPUMP aerobics class by following the instruction from a video 

recording (BODYPUMP Release 37). In addition to the video recording a BODYPUMP instructor was 

present to monitor the subject and provide assistance. The class was performed in a well-ventilated space 

and subjects were allowed to drink water during breaks in the class. Heart rate was monitored 

continuously. 

Determination of EPOC 

At the conclusion of the class a blood lactate sample was taken and the subject was reconnected to the 

gas analysis equipment for an initial period of 15 minutes and then 5 minutes every 15 minutes thereafter, 

until 60 minutes had passed since the conclusion of the class. Further blood lactate samples were taken at 

15, 30 and 60 minutes post-class. Oxygen consumption in excess of RMR was calculated and plotted as a 

function of time. Total EPOC was taken as the area under the curve. 


Figure 1: Measurement of Resting Metabolic Rate (RMR) 

Table 5: Schedule of EPOC session 

Duration Activity 

6:30am-7:00am Seated Rest 

7:00am-7:15am Determination of RMR 

7:15am-8:15am BODYPUMP class 

8:15am-8:30am EPOC collection 1 







RESULTS 

This study sought to quantify the excess post-exercise oxygen consumption (EPOC) that occurs as a result 

of performing a BODYPUMP class. Twelve male subjects performed two sessions; the first consisting of 

body composition assessment and a VO2 max test and the second an EPOC session which consisted of a 

BODYPUMP class and pre-and post-measurement of metabolic rate. Results are presented in Tables 6- 

12. 


Table 6: Body composition and VO2 max of subjects 


ISAK Sum of 8 Skinfolds (mm) 79.3 (25.7) 

Percent Body Fat 13.2 (3.2) 

Lean Body Mass (kg) 70.0 (4.1) 

VO2 max (L/min) 4.37 (0.60) 

VO2 max (ml/kg/min) 54.7 (7.2) 

Maximum Heart Rate 183.3 

The subjects were generally of moderate-high aerobic fitness and had on average, 70 kg of lean body 

mass. During the BODYPUMP class the average (SD) heart rate was 118 (19) which was 64 (9)% of 

each individual’s maximum heart rate. Subjects spent an average of 20 minutes above 70% of maximum 

heart rate. 

Table 7: Subjects heart rate during BODYPUMP class 



Average Heart Rate During Class 118 (19.0) 

Average Heart Rate during class as a % of Maximum Heart Rate 64 (9.0) 

Maximum Heart Rate During Class 150 (21.0) 

Maximum Heart Rate during class as a % of Maximum Heart Rate 82 (11.0) 

Minutes Above 50% Maximum Heart Rate 53 (3.0) 




Minutes Above 90% Maximum Heart Rate 0.3 (0.7) 

Table 8: Subject loads during BODYPUMP class 

Track / Muscle Group Load (kg) Mean (SD) 

Warmup 15.4 (1.4) 

Legs (Squats) 37.9 (8.6) 

Chest 28.3 (5.5) 

Back 26.7 (6.9) 

Triceps 15.8 (3.3) 

Biceps 15.6 (2.6) 

Legs (Split Squats/Lunges) 19.8 (8.6) 

Shoulders 14.2 (3.4) 

Total Class Load 173.8 (33.5)

The loads used during the current study provide an indication of what male subjects with moderate to high 

experience use during a BODYPUMP class. These numbers are in stark contrast to loads used by 

Stanforth et al (2000) in their assessment of aerobic demand of BODYPUMP. 

Table 9: Blood Lactate Concentration following BODYPUMP 

Table 10: Resting Metabolic Rate and EPOC of subjects 


Resting Metabolic Rate (kcal/min) 1.26 (0.31) 

Resting Metabolic Rate (LO2/min) 0.254 (0.064) 

EPOC (kcal) 38.95 (10.2) 

EPOC (LO2) 7.63 (2.1) 

EPOC (kcal per 80 kg body mass) 39.62 (12.1) 

EPOC (LO2 per 80 kg body mass) 7.8 (2.4) 

EPOC (kcal per 70 kg of lean body mass) 39.05 (10.5) 

EPOC (LO2 per 70 kg of lean body mass) 7.7 (2.1) 

EPOC following BODYPUMP was 38.95 kcal with a range of 27.4 kcal to 61.7 kcal. An average of 7.63 

liters of oxygen was consumed in addition to resting levels in the 60 minutes following the class. 

Table 11: EPOC of experienced and inexperienced BODYPUMP subject 

Group Mean (SD) EPOC 

Experienced (n=5) 32.3 (4.9) 

Inexperienced (n=7) 43.7 (10.6) 

Experienced subjects produced an average EPOC of 32.3, while the inexperienced subjects produced an 

average of 43.7 kcal. 

Time of Sample Lactate Concentration (mmol/L) 

Resting 1.83 (0.4) 

During Cooldown Track 6.41 (2.0) 

15 Minutes Post-Class 3.65 (1.3) 




Table 12: Relationship between load, intensity and EPOC 

Load 


Average HR during class as a 

% of Maximum HR 

VO2 

max 

EPOC -0.6916 0.123 -0.525 

Load 0.388 0.712 

Average HR during class as a % of 

Maximum HR 

DISCUSSION 

-0.4152 

Excess post-exercise oxygen consumption may be an important consideration for many reasons, including 

its possible effect on body mass and body composition. The EPOC values reported in previous research 

investigating traditional resistance or aerobic exercise range from 9.3 to 95 kcal. The average EPOC found 

in the current study was 38.95 kcal. When scaled to a body mass of 80 kg, this value was 39.62 kcal and 

when scaled to 70 kg of lean body mass, this value was 39.0 kcal. These values are similar to values 

reported by other authors. 

The finding of previous research [14,23] , differed with regard to calorie consumption during a BODYPUMP 

session. Pfitzinger et al (1999) reported 486 (81.9) kcal, while Stanforth et al. (2000) reported 308 (42) kcal 

for an 80 kg male. The methodological differences between these two studies that explain the variation in 

findings are in the selection of subjects (experienced vs novice) and the exercise intensity (high vs low). 

Using the average of these studies we can estimate that a typical 80 kg male (neither experienced nor 

inexperienced) performing a BODYPUMP class will consume approximately 397 kcal. In addition to this, 

they will consume approximately 40 calories in the post-exercise period. As shown in Table 13 (below) this 

represents a total caloric expenditure of 437. 

Table 13: Total calorie consumption associated with a BODYPUMP session 

BODYPUMP + EPOC = TOTAL ENERGY EXPENDITURE 

397 + 40 = 437 

The EPOC measured in this study equates to approximately 10% of the previously measured calorie 

consumption during the class. This relationship is very general, however, as illustrated by the fact that 

heavier subjects tended to consume more calories during a BODYPUMP class while some of the highest 

individual EPOC levels in the current study were recorded by some of the lightest subjects. 

Previous research has suggested that subject fitness level and experience with the particular exercise 

session has a major role in the size of EPOC. Fitness level as represented by VO2 max was moderately 

negatively correlated (r = -0.525), with EPOC lending some support to the notion that a higher VO2 max will

esult in a lower EPOC. Unfortunately, defining fitness level using VO2 max does not identify those subjects 

who were experienced with BODYPUMP. There were five subjects who were regular participants 

(experienced) of BODYPUMP and there were seven subjects who were not regular participants 

(inexperienced). The EPOC of the experienced subjects was 32.3 (4.9) kcal as compared to 43.7 (10.6) 

kcal for the inexperienced subjects. This difference was statistically significant at the 0.05 level. The 

relationship between load and EPOC was unexpected. There was a correlation of –0.69 between total load 

used by the subjects (the sum of the load used for all the tracks) and EPOC. This suggests that the lower 

the load, the higher the EPOC. Upon consideration of the individual data it was clear that this represented 

the difference between experienced and inexperienced subjects. Experienced subjects used greater loads 

but produced lesser amounts of EPOC compared to the inexperienced subjects. This suggests that the 

stimulus that BODYPUMP was providing was having a lesser effect on the experienced subjects despite 

the increased loads. There was a moderate-strong correlation (r=0.712) between aerobic fitness and load 

used during BODYPUMP. This suggests that a moderate to high level of aerobic fitness improves the 

ability to work hard and use high loads during BODYPUMP. 

Measuring EPOC in such a controlled manner is necessary to determine the exact amount of calories 

consumed in excess of resting metabolic rate. However, in reality, a person finishes a class and continues 

to be active as they shower, eat and perform daily activities. This may prolong and enhance the EPOC 

associated with exercise. EPOC in excess of 24 hours has been reported; however, daily activities were 

performed and three meals were eaten in this time. More research needs to be performed on how meals 

and daily activities prolong EPOC. 

The EPOC response has two components; a fast component and a slow component. The fast component 

of EPOC is the first few minutes after exercise finishes where metabolic rate is considerably elevated. This 

large elevation rapidly decreases and is followed by a slow component where metabolic rate is only slightly 

elevated and gradually returns to resting levels. Blood lactate concentrations provide some insight to the 

recovery of the body following exercise. Table 9 shows that lactate average levels were 6.41 at the 

immediate conclusion of the class but had decreased to 3.65 within 15 minutes and 2.54 within 30 minutes. 

As the subjects were required to sit quietly following the class the lactate removal processes were not given 

much assistance. Had normal post-class activities been performed this removal would have been much 

more rapid. If metabolic rate had been measured from the end of the final workout track (the start of the 

cooldown track) then EPOC would likely have been much higher as there would have been an extra five 

minutes of data during the fast component of EPOC. 

SUMMARY 

The EPOC following BODYPUMP is similar to that measured following other activities such as treadmill 

running, cycling, resistance training and circuit training. This EPOC was equivalent to approximately 10% of 

the previously measured exercise sessions’ calories. EPOC was affected by level of experience with the 


class but no significant relationships were found between load, VO2 max or exercising heart rate and 

EPOC. The main points of the study are: 

a) The average (SD) EPOC following BODYPUMP was 38.95 (10.2) kcal. 

b) Subjects who were inexperienced with BODYPUMP and not regular class participants had 

higher EPOC levels than those who were experienced and regular participants 

c) Average heart rates during BODYPUMP were 64% of maximum heart rate 

The notion that regular performance of BODYPUMP reduces body fat has experimental and anecdotal 

support. The role that EPOC plays in this reduction in body fat was previously unclear. EPOC contributes 

approximately 40 kcal to daily energy expenditure if a BODYPUMP session is performed. These 

additional calories may contribute to an accelerated improvement in body composition. 

To date, BODYPUMP is a relatively unresearched type of exercise. Areas of future research should 

include the further documentation of exercise intensities (as indicated by heart rate) in a large and diverse 

population and a replication of the study investigating the longitudinal effects of BODYPUMP on body 

composition. 


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BODYPUMP Research Report - Les Mills

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