Running patterns and force-velocity sprinting profiles in elite training young soccer players: A cross-sectional...

The Volodalen® field method permits to classify runners into aerial or terrestrial, based on vertical oscillation, upper-body motion, pelvis and foot position at ground contact, and foot strike pattern. The present study aimed to compare the sprint running force-velocity profiles between aerial and terrestrial runners. Sixty-Four French National-Level young soccer players (28 females, 36 males) performed three trials of unloaded maximal 40 m sprints. External horizontal power-force-velocity relationships were computed using a validated biomechanical model and based on the velocity-time curve. Accordingly, the participants were classified into patterns in aerial and terrestrial runners. Terrestrial runners showed a higher maximal horizontal force (F₀) (6.73 ± 1.03 vs 6.01 ± 0.94 N·kg^-1), maximal horizontal power (P_max) (14.04 ± 3.24 vs 12.51 ± 3.31W·kg^-1), maximal acceleration (Acc) (6.83 ± 0.85 vs 6.26 ± 0.89 m·s^-2), and maximal rate of horizontal force (RF_max) (57.41 ± 4.64 vs 52.81 ± 5.69%) compared to aerial runners. In contrast, terrestrial runners displayed a more negative rate of decrease of RF (D_RF) (-11.65 ± 1.71 vs -10.23 ± 1.66%) and slope of the Force-Velocity relationship (F-V slope) (-0.83 ± 0.11 vs -0.77 ± 0.10 N·s·m^-1·kg^-1) than aerial runners. The results indicate that terrestrial runners displayed more efficient force production in the forward direction and displayed more "force-oriented" F-V profiles. Nevertheless, aerial runners were more effective in maintaining a net horizontal force production with increasing speed. Our results suggest that terrestrial runners could be more adapted to the specific short distance and high acceleration sprints running.