Thursday-Abstracts

Thursday, May 30, 2013
S210 Vol. 45 No. 5 Supplement
Oxygen consumption was greater in ARM and FWD compared to UR (25.59±3.91,
24.98±3.81 vs. 23.51±3.90 ml/kg/min, P < 0.05), but ARM and FWD were not
different from each other (P = 0.19). This similarity was in spite of the active use of
additional arm musculature during ARM not present in FWD. Additional subjects will
be collected to confirm these preliminary findings.
CONCLusION: For this exercise modality, utilizing one’s arms or leaning forward
while anchoring the upper body resulted in similar increases in heart rate and oxygen
consumption relative to an unstabilized upright posture at the same machine settings.
Supported by Cybex International Inc.
1129 Board #74 May 30, 9:00 AM - 10:30 AM
Cross-Validation of a recently Published Equation
Predicting Energy Expenditure to run or Walk a Mile
Cody E. Morris, Mark Loftin, FACSM, Scott Owens, Dwight
Waddell, Martha Bass, John Bentley. The University of
Mississippi, University, MS.
(No relationships reported)
PurPOsE: Establishing a caloric prediction equation based on distance walked or run
rather than time is an important goal in attempting to more accurately estimate energy
expenditure (EE). The primary purpose of this study was to cross-validate the recently
published Loftin et al. (2010) prediction equation for walking or running a mile.
METhOds: Participants consisted of 10 normal weight walkers (NWW), 10
overweight walkers (OW), and 10 distance runners (DR). Gender was balanced across
sub-groups. Participants walked or ran for 5 minutes at their preferred pace. Preferred
walking pace was determined by six timed 50-ft trials and preferred running pace
was determined by the runner’s preferred training pace. Energy expenditure (EE) was
determined via indirect calorimetry and reported in absolute units (kcal), and corrected
to a mile distance. Body composition was assessed via DXA. EE per mile was
predicted using the Loftin, et al. (2010) equation.
rEsuLTs: Absolute EE per mile for the cross-validation (CV) group was similar
across sub-groups (NWW = 100.2 kcal/mile, OW = 115.6 kcal/mile, DR = 107.8
kcal/mile) and did not show significant difference between groups (p > 0.05). The
overall mean for the absolute EE was 107.8 + 15.5 kcal/mile. The Loftin, et al. (2010)
equation yielded an overall mean for the predicted EE per mile of 99.7 + 10.9 kcal/
mile. This was significantly different (p < 0.05) than the mean actual value from the
cross-validation group, although the difference was within the published standard error
of the estimate (SEE) of the original equation (SEE = 10.9 kcal/mile). A regression
equation for the CV group produced an R2 of 0.605 and the SEE (9.8 kcal/mile) was
similar to the original equation. Further, a Chow test found no significant differences
(p > 0.05) between regression coefficients of the original equation and the CV group
equation and the estimated shrinkage on cross-validation was 0.027; which is minimal
and suggestive of no significant difference in R2 values.
CONCLusIONs: The cross-validation results support the original equation (Loftin
et al., 2010) as valid. We suggest the Loftin, et al. (2010) regression equation is useful
for exercise prescription in that it allows for the prediction of EE for either walking or
running a mile in normal weight and overweight adults.
1130 Board #75 May 30, 9:00 AM - 10:30 AM
Total Energy Expenditure and Energy Expenditure Per
Kilogram of Body Weight Comparison among young adults
Vivek K. Prasad, Gregory A. Hand, FACSM, Jason R. Jaggers,
Robin P. Shook, Amanda Paluch, Stephanie Burgess, Xuemei
Sui, Steven N. Blair, FACSM. University of South Carolina,
Columbia, SC.
(No relationships reported)
PurPOsE: Total energy expenditure (EE) consists of resting EE which account
for approximately 60% of total EE (mainly due to metabolic cost of processes);
10% accounts for the thermal effect of feeding; and 30% accounts for nonresting EE
(remaining expenditure of energy, mainly in the form of physical activity). All the
above processes for EE depend upon body composition to a great extent. The present
study was designed to compare overweight and normal weight participants for their
total EE and EE per kilogram (KG) body weight.
METhOds: A group of healthy women and men were assessed for body fat (BF)
percent and BMI. BF percentage was calculated as the percentage of total weight
identified as fat tissue by dual x-ray absorptiometry (DXA). BMI was calculated as
measured weight in KG/ht in meters². Participants were categorized into overweight
and normal weight groups according to BF percent and BMI. Overweight cut points
by BF percent were ≥19.5% and ≥25.4% for men and women, respectively, where as
normal weight cut points were ≤19.4% and ≥25.3% for men and women, respectively.
BMI overweight and normal weight cut points were ≥25.0 and ≤24.9 KG/ht in meters²
for both men and women. T-tests were used to compare means of EE (total and per KG
body weight) between overweight and normal weight by gender.
rEsuLTs: The study population consisted of 429 healthy young adults (212 men
and 217 women; aged 21 to 35 years). In the BF percent classifications we found
overweight and normal weight participants had no difference in total EE, but normal
weight participants were expending significantly higher energy per KG body weight
MEDICINE & SCIENCE IN SPORTS & EXERCISE ®
(p < 0.001). When classified by BMI, overweight participants expended significantly
higher overall energy than the normal weight group (p = 0.023 for men; and