Quantification of Velocity Decrement and Kinetic Profile during 10 metre Resisted Sprinting using the Run RocketTM

Abstract

The Run Rocket^TM is used to improve acceleration and maximum velocity sprinting performance. However, no empirical data exist to support its efficacy. Accordingly, this study aimed to examine how incremental Run Rocket^TM loads effect sprint velocity (V_dec), relative ground impulse and relative peak force. Fourteen recreationally active (13 male, 1 female) participants performed 10 m sprints at three Run Rocket^TM arbitrary (AU) resistance levels (10, 20 and 30 AU and unresisted sprints). One-way repeated measures ANOVA, and Cohen’s d effect sizes identified significant and meaningful differences between conditions. Run Rocket^TM induced significant, large (d= >4.50) V_dec across all conditions. First and second step ground contact times showed large effects (d= >2.50) when comparing unresisted sprinting to all Run Run Rocket^TM conditions. Concomitant moderate increases were observed for first and second step relative horizontal propulsive impulses, while first and second step relative horizontal propulsive forces showed no effect, suggesting V_dec was attributable to increases in ground contact time during resisted sprinting using the Run Rocket^TM in all conditions. The results indicate most Run Rocket^TM resistance levels might be too challenging to improve maximum velocity sprinting, yet not challenging enough to improve acceleration. Therefore, lighter Run Rocket^TM resistances may be preferential.