The Effects of Sports Drinks During High-Intensity Exercise on the Carbohydrate Oxidation Rate Among Athletes: A Systematic Review and Meta-Analysis.

This study examines the effects of sports drinks ingestion during high-intensity exercise for carbohydrate oxidation rate (CHO-O) among athletes. PubMed, Embase, and the Cochrane library were searched for available papers published up to November 2019. The primary outcome is the carbohydrate oxidation rate (CHO-O), and the secondary outcome is the fat oxidation rate (Fat-O). Statistical heterogeneity among the included studies was evaluated using Cochran's Q test and the I index. The random-effects model was used for all analyses, regardless of the I index. Five studies are included, with a total of 58 participants (range, 8-14/study). All five studies are randomized crossover trials. Compared to the control beverages, sports drinks have no impact on the CHO-O of athletes [weighted mean difference (WMD) = 0.29; 95% CI, -0.06 to 0.65, = 0.106; I = 97.4%, < 0.001] and on the Fat-O of athletes (WMD = -0.074; 95% CI, -0.19 to 0.06, = 0.297; I = 97.5%, < 0.001). Carbohydrate-electrolyte solutions increase CHO-O (WMD = 0.47; 95% CI, 0.08-0.87, = 0.020; I = 97.8%, < 0.001) but not Fat-O (WMD = -0.14; 95% CI, -0.31 to 0.03, = 0.103; I = 98.2%, < 0.001). Caffeine has a borderline effect on Fat-O (WMD = 0.05; 95% CI, 0.00-0.10, = 0.050). Compared with the control beverages, sports drinks show no significant improvement in CHO-O and Fat-O in athletes. Carbohydrate-electrolyte solutions increase CHO-O in athletes but not Fat-O.