Biomechanics and Medicine in Swimming XI

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Bench Press and Leg Press Strength and its Relationship with In-Water Force and Swimming Performance when Measured in-season in Male and Female Age-group Swimmers carl, d.l., leslie, n., dickerson, t., Griffin, B., Marksteiner, A. University of Cincinnati, Cincinnati Ohio, USA The purpose of this study was to determine if two standard measurements of dry land strength would correlate with the ability to generate in-water force. Participants were 25 male and female age-group swimmers. One repetition max lifts were established for the Bench Press (BP) and Leg Press (LP) and correlated with in-water force generation as measured during tethered swimming (TeS). They were also correlated with swimming performance using a timed 22.9-m (25y) swim. A significant correlation existed between BP strength and both TeS and 25y tests (r = 0.82 and 0.84 respectively, p< 0.01) A minor correlation existed between LP and 25y (R = 0.70, p< 0.01). No significant correlation existed between LP and TeS (r= 0.50, p< 0.01). In addition, males demonstrated stronger correlations than females in all cases. In conclusion, BP strength may be an appropriate alternative to established methods as an indicator of in-water force generation and swimming performance in older age-group swimmers. Key words: swimming, tethered swimming, Bench Press, leg Press IntroductIon In recent years, USA-Swimming launched a series of educational programs and databases designed to quickly and efficiently disseminate information to their entire coaching membership. One such program is the Land / Water Strength Test (LWST; Sokolovas, 2007 and USA- Swimming, 2007) database. The purpose of the LWST is to assess swimming-specific strength on land and to determine how effectively it transfers into the generation of force while in the water. Depending upon the relationship observed, a coach could make personalized adjustments in the swimmers strength training program and or their stroke efficiency. If the relationship is high between land and water strength then it might be suggested that the coach design a resistance training program to enhance overall strength in an effort to improve performance. Conversely, if the relationship is low it would be desirable for the coach and athlete to focus on correcting stroke efficiency, more so, than the overall strength of the swimmer. To assess dry land strength, USA-Swimming recorded maximum effort strength during isometric contractions on a Vasa Trainer swim bench. To our knowledge, additional testing measures have not been conducted to determine whether other forms of land strength are equally beneficial in establishing discrepancies between land and in-water strength measurements. Therefore, it was the purpose of this study to determine if two standard measurements of dry land strength, bench press (BP) and leg press (LP), would correlate with the ability to generate force in water, as measured during tethered swimming, and whether they would correlate with sprint swimming performance as measured by a timed 22.9m swim. Methods Twenty five (10 male, 15 females) highly competitive age-group swimmers ranging from National qualifiers to High School competitors volunteered to participate in the study. Their mean (+ SD) age, weight and height were 16.6 + 1.3 years, 71.6 + 17.3 kg, and 181.6 + 3.8 cm for males and 16.3 + 0.9 years, 62.0 + 2.9 kg, and 168.2 + 4.6 cm for females respectively. Each participant in the study trained on a year-round basis. The study was approved by the institutional review board at the University of Cincinnati with all subjects completing an informed consent document. chaPter4.trainingandPerformance Each subject completed a single day testing session that consisted of a randomized distribution of the following activities: Swim Training: Prior to the in-water testing, each subject completed a standardized 1371-m warm-up. Completion of the 2 in-water tests was completed in randomized order. 22.9-m Swim Test: Each subject completed two 22.9-m maximal effort swims from the starting block. Each swim was separated by a minimum of 5 minutes. Active recovery swimming was allowed at the discretion of each subject. Times were recorded to the 100 th of a second and the two trials were averaged for best time and recorded. Tethered maximal effort swim: Each subject completed two in-water tethered maximal force generation swims (Digital Force Gauge, IMADA, Inc). Each subject was instructed to go all out from a push for 10 seconds. Maximal force generated was recorded in Newton’s and the two trials averaged for best effort and recorded. Each trial was separated by a minimum of 1 minute rest. Resistance Training: Prior to the land testing each subject participated in some light lifting for the benefit of warming up. Completion of the two land strength tests was completed in randomized order. Bench Press: Subjects completed a standard barbell chest press to determine a one repetition maximum (1RM). The following protocol was established. Each subject began with a warm up set consisting of light weight for 10-15 repetitions. Subjects then completed a set of moderate weight for 10 repetitions followed by a minimum of 2 minutes rest. The weight was increased by 10-20 % and another set of 10 repetitions was completed. This procedure was continued until the subject was unable to complete ten full repetitions. 1RM BP was estimated using the following equation (Brzycki 1993): Lifting weight (in pounds) / (1.0278-(.0278 x no. of reps)). Leg Press: To establish a 1RM LP, subjects completed a bilateral seated leg press following the same established protocol (Brzycki 1993) that was used for the 1RM BP. Descriptive statistics (mean and SD) were calculated for subjects characteristics (age, height, and weight). Pearson’s product moment correlation coefficient (r) was used to explore the relationships among different variables. The level of significance was set at p ≤ 0.01. results Table 1 summarizes the correlation coefficients for each of the variables measured. A significant correlation was found to exist between BP strength and both the TeS and the 22.9m swim respectively (r = 0.82 & 0.84). The relationship between BP and TeS and between BP and 22.9m swim time is shown in figures 1 and 2 respectively. The correlation between LP and the 22.9-m swim time was not as strong as the BP (r = 0.70). In addition, no significant correlation existed between LP and TeS force generated. However, further analyses revealed that when the males were separated from the females, significant correlations were found between all variables measured in both testing sessions including LP vs TeS (Table 1). Table 1. Mid season r-values for correlation between land strength and in-water force generation measurements. P < 0.01; BP bench press, LP leg press, 25 22.9-m swim, TeS tethered swim. Bold indicates significant correlation. Correlation Combined Males Females LP vs 25 0.702409 0.752053 0.232553 LPrel vs 25 0.279929 LP vs TeS 0.504378 0.708448 0.282953 LPrel vs TeS 0.0782 BP vs TeS 0.819576 0.732068 0.560393 BPrel vs TeS 0.694141 BP vs 25 0.841623 0.871575 0.387719 BPrel vs 25 0.813758 247
BiomechanicsandmedicineinswimmingXi dIscussIon The relationship between various power measurements and swimming performance has been well established (Sharp et al., 1982; Hawley et al., 1992 & Swaine (1994). Often measured using a modification of the Wingate Anaerobic test, what has not been established to our knowledge is the relationship between swimming performance and more practical forms of general strength. Following the protocols established by USA-Swimming’s Land / Water Strength Testing, a common measurement of strength, the 1RM BP, can be used with success when addressing imbalances between land strength and swimming performance. With the relative ease associated with the measurement of a 1RM BP, this protocol may be more readily useable for a majority of swimming programs. Although the correlation data for the 1RM leg press was not as strong as the bench press it too may be useful in developing an overall individualized picture of a swimmer. The combination of the two measurements would allow a coach to look at both upper and lower body strength separately and in combination as they translate to swimming performance. Although not a part of this study, the USA-Swimming protocol includes a kicking component and therefore the measurement of LP strength warrants further investigation into its potential effectiveness. Interestingly, when separating the females from the males in this study, weaker correlations were observed for all measurements taken. It is believed that this discrepancy may have been the result of the males having a greater amount of muscle mass than their female counterparts (Carter & Ackland 1994). In addition, there may have been more familiarity with strength training for the males than the females and this may have had an effect on the measurements of each subject’s 1RM’s. Also, this could have been due to greater homogeneity within each group. Participant group heterogeneity/homogeneity can affect the correlations like these. In addition, the data revealed similarity between the mid season and the post season testing sessions for all measurements taken. It is our belief that this lends support to the usefulness of this type of strength testing. This may indicate that regardless of the stress levels associated with training, the relationship between land strength and in-water force generation is strong and is relevant throughout the entire swimming season including through the taper period. Figure 1. The relationship between BP and timed 22.9m swim combined for males and females. (r = 0.84, p ≤ 0.01) 248 Tethered Swim (kg.) 60 55 50 45 40 35 30 25 y = 0.3144x + 21.374 20 30 40 50 60 70 80 90 100 Bench Press (kg) Figure 2. The relationship between BP and TeS for combined males and females. (r = 0.82, p ≤ 0.01) Limitations to this study include the relatively small number of subjects involved. This potential issue was heightened when the males and females were separated and the subject numbers were even smaller. The second limitation to our study is the methods used for the determination of the 1RM’s. Although a widely accepted approach to the measurement of 1RM, the protocol is still susceptible to error in prediction. conclusIon In conclusion, bench press strength may be an appropriate alternative to the established USA-swimming methods, for measuring strength as an indicator of discrepancy between swimming-related strength and either in-water force generation or sprint swimming performance. reFerences Brzycki, M. (1993) Strength testing: Predicting a one-rep max from reps-to-fatigue. JOPERD 64, 88-90. Carter, J. E. & Ackland, T.R. (1994). Kinanthropometry in aquatic sports. A study of world class athletes. In: Carter JE, Ackland TR, eds. Human Kinetics Sport Science Monograph Series, vol. 5. Chanpaing, IL, Human Kinetics. Hawley, J.A., Williams, M.M., Vickovic, M.M. & Handcock, P.J. (1992). Muscle power predicts freestyle swimming performance. Br J Sports Med. Sep;26(3), 151-5. Land / Water Strength Test. USA Swimming Web site. http://www. usaswimming.org/ USASWeb/ViewMiscArticle.aspx?TabId=977 &Alias=Rainbow&Lang=en&mid=2811&ItemId=2445. Accessed January 11, 2010. Sharp, R.L., Troup, J.P. & Costill, D.L. (1982). Relationship between power and sprint freestyle swimming. Med Sci Sports Exerc, 14(1), 53-6. Sokolovas, G. (2007). Personal communication. Swaine, I.L. (1994). The relationship between physiological variables from a swim bench ramp test and middle-distance swimming performance. Journal of Swimming Res 10, 41-48
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Pahlen Norge AS Pahlen Norge AS Cha
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