Caffeine supplementation and multiple sprint running performance

Purpose: The aim of this study was to examine the effects of caffeine supplementation on multiple sprint running performance. Methods: Using a randomized double-blind research design, 21 physically active men ingested a gelatin capsule containing either caffeine (5 mg-kg^-1 body mass) or placebo (maltodextrin) 1 h before completing an indoor multiple sprint running trial (12 × 30 m; repeated at 35-s intervals). Venous blood samples were drawn to evaluate plasma caffeine and primary metabolite concentrations. Sprint times were recorded via twin-beam photocells, and earlobe blood samples were drawn to evaluate pretest and posttest lactate concentrations. Heart rate was monitored continuously throughout the tests, with RPE recorded after every third sprint. Results: Relative to placebo, caffeine supplementation resulted in a 0.06-s (1.4%) reduction in fastest sprint time (95% likely range = 0.04-0.09 s), which corresponded with a 1.2% increase in fatigue (95% likely range = 0.3-2.2%). Caffeine supplementation also resulted in a 3.4-bpm increase in mean heart rate (95% likely range = 0.1-6.6 bpm) and elevations in pretest (+0.7 mmolL^-1; 95% likely range = 0.1-1.3 mmolL^-1) and posttest (+1.8 mmolL^-1; 95% likely range = 0.3-3.2 mmolL^-1) blood lactate concentrations. In contrast, there was no significant effect of caffeine supplementation on RPE. Conclusion: Although the effect of recovery duration on caffeine-induced responses to multiple sprint work requires further investigation, the results of the present study show that caffeine has ergogenic properties with the potential to benefit performance in both single and multiple sprint sports.