title: Caffeine supplementation and peak anaerobic power output.
abstract: The aim of this study was to investigate the effects of caffeine supplementation on peak anaerobic power output (Wmax). Using a counterbalanced, randomised, double-blind, placebo-controlled design, 14 well-trained men completed three trials of a protocol consisting of a series of 6-s cycle ergometer sprints, separated by 5-min passive recovery periods. Sprints were performed at progressively increasing torque factors to determine the peak power/torque relationship and Wmax. Apart from Trial 1 (familiarisation), participants ingested a capsule containing 5 mg·kg(-1) of caffeine or placebo, one hour before each trial. The effects of caffeine on blood lactate were investigated using capillary samples taken after each sprint. The torque factor which produced Wmax was not significantly different (p ≥ 0.05) between the caffeine (1.15 ± 0.08 N·m·kg(-1)) and placebo (1.13 ± 0.10 N·m·kg(-1)) trials. There was, however, a significant effect (p < 0.05) of supplementation on Wmax, with caffeine producing a higher value (1885 ± 303 W) than placebo (1835 ± 290 W). Analysis of the blood lactate data revealed a significant (p < 0.05) torque factor × supplement interaction with values being significantly higher from the sixth sprint (torque factor 1.0 N·m·kg(-1)) onwards following caffeine supplementation. The results of this study confirm previous reports that caffeine supplementation significantly increases blood lactate and Wmax. These findings may explain why the majority of previous studies, which have used fixed-torque factors of around 0.75 N·m·kg(-1) and thereby failing to elicit Wmax, have failed to find an effect of caffeine on sprinting performance.
authors.affiliation: a School of Sport, Health, and Applied Sciences , St Mary's University , Twickenham , UK.
authors.forename: Mark
authors.initials: M
authors.lastname: Glaister
authors.forename: Daniel
authors.initials: D
authors.lastname: Muniz-Pumares
authors.forename: Stephen D
authors.initials: SD
authors.lastname: Patterson
authors.forename: Paul
authors.initials: P
authors.lastname: Foley
authors.forename: Gillian
authors.initials: G
authors.lastname: McInnes
mesh_terms: D000328:Adult; D015308:Anaerobic Threshold / Q000187:drug effects*; D000704:Analysis of Variance; D054874:Athletic Performance / Q000502:physiology*; D002110:Caffeine / Q000008:administration & dosage / Q000097:blood / Q000494:pharmacology*; D006801:Humans; D019344:Lactic Acid / Q000097:blood; D008297:Male; D012420:Running / Q000502:physiology*; D019415:Torque; D055815:Young Adult
chemical_list: D019344:Lactic Acid; D002110:Caffeine
keywords: Wingate; ergogenic aid; peak power; sprinting