Effects of sodium phosphate and caffeine ingestion on repeated-sprint ability in male athletes. Issue 3 (March 2016)

• Record Type: Journal Article
• Authors: Kopec, Benjamin J.; Dawson, Brian T.; Buck, Christopher; Wallman, Karen E.
• Is Part Of: Journal of science and medicine in sport. Volume 19:Issue 3(2016:Mar.)
• Page Start: 272
• Page End: 276
• Publication Date: 2016-03
• Subjects: Dietary supplements -- Aerobic exercise -- Sports performance -- Team-sports; Sports sciences -- Periodicals; Sports medicine -- Periodicals; Exercise -- Physiological aspects -- Periodicals; Sports -- physiology -- Periodicals; Sports Medicine -- Periodicals; Sportgeneeskunde; 617.102705
• DOI: 10.1016/j.jsams.2015.04.001
• Languages: English
• ISSNs: 1440-2440

Abstract

Abstract: Objectives: To assess the effects of sodium phosphate (SP) and caffeine supplementation on repeated-sprint performance. Design: Randomized, double-blind, Latin-square design. Methods: Eleven team-sport males participated in four trials: (1) SP (50 mg kg −1 of free fat-mass daily for six days) and caffeine (6 mg kg −1 ingested 1 h before exercise); SP + C, (2) SP and placebo (for caffeine), (3) caffeine and placebo (for SP) and (4) placebo (for SP and caffeine). After loading, participants performed a simulated team-game circuit (STGC) consisting of 2 × 30 min halves, with 6 × 20-m repeated-sprint sets performed at the start, half-time and end of the STGC. Results: There were no interaction effects between trials for first-sprint (FS), best-sprint (BS) or total-sprint (TS) times ( p > 0.05). However, SP resulted in the fastest times for all sprints, as supported by moderate to large effect sizes (ES; d = 0.51–0.83) and 'likely' to 'very likely' chances of benefit, compared with placebo. Compared with caffeine, SP resulted in 'possible' to 'likely' chances of benefit for FS, BS and TS for numerous sets and a 'possible' chance of benefit compared with SP + C for BS (set 2). Compared with placebo, SP + C resulted in moderate ES ( d = 0.50–0.62) and 'possible' to 'likely' benefit for numerous sprints, while caffeine resulted in a moderate ES ( d = 0.63; FS: set 3) and 'likely' chances of benefit for a number of sets. Conclusions: While not significant, ES and qualitative analysis results suggest that SP supplementation may improve repeated-sprint performance when compared with placebo.