Post-exercise Ingestion of Carbohydrate, Protein and Water: A Systematic Review and Meta-analysis for Effects on Subsequent Athletic Performance.

Abstract

Athletes may complete consecutive exercise sessions with limited recovery time between bouts (e.g.≤4h). Nutritional strategies that optimise post-exercise recovery in these situations are therefore important. This two-part review investigated the effect of consuming carbohydrate (CHO) and protein with water (W) following exercise on subsequent athletic (endurance/anaerobic exercise) performance. Studies were identified by searching the online databases SPORTDiscus, PubMed, Web of Science and Scopus. Investigations that measured endurance performance (≥5min duration)≤4h after a standardised exercise bout (any type) under the following control vs. intervention conditions were included: Part 1: W vs. CHO ingested with an equal volume of W (CHO+W); and, Part 2: CHO+W vs. protein (PRO) ingested with CHO and an equal volume of W (PRO+CHO+W), where CHO or energy intake was matched. Publications were examined for bias using the Rosendal scale. Random-effects meta-analyses and meta-regression analyses were conducted to evaluate intervention efficacy. The quality assessment yielded a Rosendal score of 63±9% (mean±standard deviation). Part 1: 45 trials (n=486) were reviewed. Ingesting CHO+W (102±50g CHO; 0.8±0.6g CHOkg-1h-1) improved exercise performance compared with W (1.6±0.7L); %Δ mean power output=4.0, 95% confidence interval 3.2-4.7 (I 2=43.9). Improvement was attenuated when participants were 'Fed' (a meal 2-4h prior to the initial bout) as opposed to 'Fasted' (p=0.012). Part 2: 13 trials (n=125) were reviewed. Ingesting PRO+CHO+W (35±26g PRO; 0.5±0.4g PROkg-1) did not affect exercise performance compared with CHO+W (115±61g CHO; 0.6±0.3g CHO·kg bodymass-1h-1; 1.2±0.6L); %Δ mean power output=0.5, 95% confidence interval -0.5 to 1.6 (I 2=72.9). Athletes with limited time for recovery between consecutive exercise sessions should prioritise CHO and fluid ingestion to enhance subsequent athletic performance. PROSPEROREGISTRATION NUMBER: CRD42016046807.