Sprint mechanical characteristics of sub-elite and recreational sprinters

The aim of this study was to explore the sprint mechanical and kinematic characteristics of sub-elite and recreational male sprinters during the acceleration phase of a linear sprint running section. Eighteen sprinters (nine sub-elite, nine recreational) performed two all-out 30-m sprints. Three high speed panning cameras were used to record the entire sprint distance continuously. The sprint velocity-time data of each camera were determined by temporal analysis of the video recording. These values were used to determine the variables of the horizontal F-v profile (theoretical maximal values of horizontal force [F0], velocity [v0], power [Pmax], the maximal ratio of horizontal to resultant force [RFmax], the decline in the ratio of horizontal force production as the running speed increases [DRF]) and key kinematic characteristics. Significant differences were observed between the groups for v0 (0.79 ± 0.24 m∙s-1, p = 0.005), Pmax (3 ± 1.17 W∙kg-1, p = 0.020) and RFmax (3.1 ± 1.2 %, p = 0.021). No statistical differences were found for F0 (0.55 ± 0.46 N∙kg-1, p = 0.25) and DRF (0.2 ± 0.5 %∙s∙m, p = 0.67). The mean running velocity and mean step rate were higher, whereas mean ground contact time was shorter in sub-elite sprinters. There were no differences in mean step length and mean flight time. The subelite sprinters in our study demonstrated the capacity to generate higher amounts of horizontal forces at higher running speeds, apply horizontal force to the ground more efficiently and achieve higher step rates during sprint acceleration than recreational sprinters.