Differences between junior and senior male sprinters in physiological variables associated with sprint performance.

Background: The physiological variables associated with sprint performance have been extensively studied. However, little information is available on how the corresponding physiological variables differ between junior and senior sprinters. This study aimed to examine this subject.

Methods: In addition to the maximal running velocity achieved while sprinting over 60-m, body composition, muscle thicknesses of the trunk and lower limbs, performance scores of four jumping tasks (countermovement, rebound, standing long, and standing five-step jumps), and 10-s maximal anaerobic pedaling power were determined in 17 junior and 22 senior male sprinters.

Results: In the junior and senior sprinters, most of the measured variables were significantly correlated with the maximal running velocity. Analysis of covariance showed that only the maximal pedaling power relative to the body mass was significantly different between the two groups in the regression equation slope of the relationship with maximal running velocity (0.20 for junior and 0.64 for senior sprinters). Additionally, multiple regression analysis revealed that while the standing five-step jump distance (40%) and the size of the psoas major muscle (23%) were selected as explanatory factors for maximal running velocity in the junior sprinters, maximal pedaling power relative to the body mass (63%) was selected in the senior sprinters.

Conclusions: This study suggests that the following physiological factors associated with sprint running performance differ between the junior and senior sprinters: the ability of repetitive jumping in the horizontal forward direction and muscularity of hip flexors in the junior sprinters versus the anaerobic capacity in senior sprinters. Therefore, coaches and athletes need to take into consideration that the physiological variables to be focused on are different for each generation.