SHORT-TERM CREATINE SUPPLEMENTATION AND REPEATED SPRINT ABILITY – A SYSTEMATIC REVIEW AND META-ANALYSIS

The aim of this study was to conduct a systematic review and meta-analysis of the effects of short-term creatine supplementation on repeated sprint ability. Fourteen studies met the inclusion criteria of adopting double-blind randomized placebo-controlled designs in which participants (age: 18 – 60 years) completed a repeated sprint test (number of sprints: 4 < n ≤ 20; sprint duration: ≤ 10 s; recovery duration: ≤ 90 s) before and after supplementing with creatine or placebo for 3 – 7 days in a dose of ~ 20 g/d. No exclusion restrictions were placed on the mode of exercise. Meta-analyses were completed using random-effects models, with effects on measures of peak power output, mean power output, and fatigue (performance decline) during each repeated sprint test presented as standardized mean difference (δ); and with effects on body mass and post-test blood lactate concentration presented as raw mean difference (D). Relative to placebo, creatine resulted in a significant increase in body mass (D = 0.79 kg; p < 0.00001) and mean power output (δ = 0.61; p = 0.002). However, there was no effect of creatine on measures of peak power (δ = 0.41; p = 0.10), fatigue (δ = 0.08; p = 0.61), or post-test blood lactate concentration (D = 0.22 L/min; p = 0.60). In conclusion, creatine supplementation may increase mean power output during repeated sprint tests; though the absence of corresponding effects on peak power and fatigue means that more research, with measurements of intramuscular creatine content, is necessary to confirm.