Background: The aims of the present study were to assess competitive sprinters' body size and composition and to determine their impact on performance.
Methods: Ninety-eight competitive male sprinters (100 m) participated in this cross-sectional study. A series of measurements was directly taken and data on muscular strength and power tests were self-reported. Body composition was assessed by skinfold method and somatotype was calculated by the Heath-Carter anthropometric method. Sprinters were classified into three groups depending on their personal best time and comparisons were performed between the athletes in the top and in the bottom tertiles. Relationships between anthropometric traits and performance were assessed by Pearson's correlation coefficients.
Results: Top sprinters had significantly greater body mass index, relaxed and contracted upper arm girths, thigh and calf girths, fat free mass and fat free mass index, and lower ectomorphy than the lowest tertile. Strength and power were significantly higher. Personal best time was significantly correlated with several anthropometric traits and indices of lean body mass.
Conclusions: Body size, composition and somatotype differ between performance levels in speed running. Being less ectomorphic, with a greater fat free mass and strength, can explain significant differences in sprinting performances. The results presented in this study provide a point of reference about sprinter characteristics, which can help coaches and sport scientists to improve sprinter performance.