Caffeine and sprint cycling performance: Effects of torque factor and sprint duration

Purpose: To investigate the influence of torque factor and sprint duration on the effects of caffeine on sprint cycling performance. Methods: Using a counterbalanced, randomized, double-blind, placebo-controlled design, 13 men completed 9 trials. In trial 1, participants completed a series of 6-s sprints at increasing torque factors to determine the torque factor, for each individual, that elicited the highest (T _optimal ) peak power output (PPO). The remaining trials involved all combinations of torque factor (0.8 N·m ⁻¹ ·kg ⁻¹ vs T _optimal ), sprint duration (10 s vs 30 s), and supplementation (caffeine [5 mg·kg ⁻¹ ] vs placebo). Results: There was a significant effect of torque factor on PPO, with higher values at T _optimal (mean difference 168 W; 95% likely range 142–195 W). There was also a significant effect of sprint duration on PPO, with higher values in 10-s sprints (mean difference 52 W; 95% likely range 18–86 W). However, there was no effect of supplementation on PPO (P = .056). Nevertheless, there was a significant torque factor × sprint duration × supplement interaction (P = .036), with post hoc tests revealing that caffeine produced a higher PPO (mean difference 76 W; 95% likely range 19–133 W) when the sprint duration was 10 s and the torque factor was T _optimal . Conclusion: The results of this study show that when torque factor and sprint duration are optimized, to allow participants to express their highest PPO, there is a clear effect of caffeine on sprinting performance.