The allometric relationship between muscle mass and the main anthropometric variables in male and female elite...

Muscle mass is estimated in athletes to measure the effects of training and determine if their muscle mass is optimized for their sport. The assessment depends on each subject's body size. The aim of the study was to analyze the most appropriate allometric relationship between muscle mass and the main size variables, as well as to define the most specific allometric indices for this population. The sample comprised 4651 elite athletes (65.3% male) from 41 sports. Muscle mass was estimated by Lee's equation using the anthropometric technique and correlated with nine anthropometric variables. Curvilinear regression was established according to an allometric model, y = a* x^b, where y is the muscle mass, x are the size variables with the highest correlation coefficient, and b is the exponent of power. The powers obtained in males vs. females were: height, 1.7 vs. 1.5; sitting height, 2.0 vs. 1.7; arm span, 1.5 vs. 1.3; biacromial breadth, 1.7 vs. 1.4; and tibial height, 1.1 vs. 1.0. These new indices will allow the assessment of muscle mass, independent of the height or chosen size variable, and the calculation of muscle mass according to the subject's dimensions.