The relationship between lean body mass and isokinetic peak torque of knee extensors and flexors in young male and female swimmers

In sprint swimming, thigh muscles strength and body composition may contribute to the development of a good performance in the water. The present study describes the relationship between lean body mass (LBM) and isokinetic peak torque (PT) of knee extensor and flexor muscles in male (n = 31) and female (n = 22) competitive swimmers aged 10 to 12 years. Skinfold thickness measurements for percent body fat and LBM were recorded. Isokinetic testing consisted of concentric knee extensions and flexions at 60degrees/s, 120degrees/s and 180degrees/s. High correlation coefficients (Pearson's r: 0.765-0.890, p < 0.001) indicated a strong relationship between LBM and knee muscles strength at all angular velocities. Using linear regression analysis, PT could be predicted from the LBM for this particular age and sex groups. However, a simple linear model between LBM and PT could not be constituted as complementary biological parameters, such as flexibility and muscular endurance could also account for the variability.