Training at maximal power in resisted sprinting: Optimal load determination methodology and pilot results in team sport athletes

<div><p>Aims</p><p>In the current study we investigated the effects of resisted sprint training on sprinting performance and underlying mechanical parameters (force-velocity-power profile) based on two different training protocols: (i) loads that represented maximum power output (<i>L</i>_opt) and a 50% decrease in maximum unresisted sprinting velocity and (ii) lighter loads that represented a 10% decrease in maximum unresisted sprinting velocity, as drawn from previous research (<i>L</i>₁₀).</p><p>Methods</p><p>Soccer [<i>n</i> = 15 male] and rugby [<i>n</i> = 21; 9 male and 12 female] club-level athletes were individually assessed for horizontal force-velocity and load-velocity profiles using a battery of resisted sprints, sled or robotic resistance respectively. Athletes then performed a 12-session resisted (10 × 20-m; and pre- post-profiling) sprint training intervention following the <i>L</i>₁₀ or <i>L</i>_opt protocol.</p><p>Results</p><p>Both <i>L</i>₁₀ and <i>L</i>_opt training protocols had minor effects on sprinting performance (average of -1.4 to -2.3% split-times respectively), and provided trivial, small and unclear changes in mechanical sprinting parameters. Unexpectedly, <i>L</i>_opt impacted velocity dominant variables to a greater degree than <i>L</i>₁₀ (trivial benefit in maximum velocity; small increase in slope of the force-velocity relationship), while <i>L</i>₁₀ improved force and power dominant metrics (trivial benefit in maximal power; small benefit in maximal effectiveness of ground force orientation).</p><p>Conclusions</p><p>Both resisted-sprint training protocols were likely to improve performance after a short training intervention in already sprint trained athletes. However, widely varied individualised results indicated that adaptations may be dependent on pre-training force-velocity characteristics.</p>