Moderate Load Resisted Sprints do Not Improve Subsequent Sprint Performance in Varsity Level Sprinters.

Resisted sprint training (RST) is commonly used for performance enhancement in athletics and team sports to develop acceleration ability. Evidence suggests that RST may be effective as a short-term intervention to improve successive sprints. While these improvements have been measured in team sport athletes, limited research has considered the acute effects of RST training in sprint-trained athletes. Therefore, the aim of the current study was to determine if performing RST with varsity level sprinters using sled-equivalent resistive loads of ∼45% body mass results in a potentiation effect, leading to improvements in subsequent maximal sprint performance over 0-5 m and 0-20 m. Competitive sprinters (n=20), were randomly assigned to perform a pre/post maximal 20 m sprint separated by either 3 resisted (RST group) or un-resisted (URS group) sprints. The RST or URS protocol was performed on four occasions separated by at least 7 days. No significant differences were observed between the RST and URS groups comparing changes in sprint times over 0-5 m (URS Δ = <0.01 s ± 0.03 s, RST Δ = <0.01 s ± 0.03 s) and 0-20 m (URS Δ = 0.013 s ± 0.04 s, RST Δ = <0.01 s ± 0.04 s). We conclude that resisted sprints using sled equivalent loads of 45% body mass are ineffective at inducing a potentiating effect on subsequent sprint performance in varsity level sprinters. In this population of trained athletes, greater loads may be necessary to induce a potentiating effect.