Sodium bicarbonate ingestion improves Yo-Yo intermittent recovery test 1 performance: a randomized crossover trial

Abstract

This study investigated the effect of sodium bicarbonate (NaHCO3-) ingestion on the Yo-Yo intermittent recovery test 1 (IR1). We tested the hypothesis that acute ingestion of NaHCO3- would increase blood lactate concentrations {[}BLa], enhance performance, and reduce rating of perceived exertion (RPE) in the Yo-Yo IR1. Eight recreationally active males (N= 8, age: 26 +/- 4 yr, height: 178 +/- 6 cm, body mass: 82 +/- 10 kg) participated in the Yo-Yo IR1 on two separate occasions, separated by 1 wk, in a randomized crossover design. Following familiarization, during seated rest, participants' pretest {[}BLa] was taken, and participants then consumed either a placebo of 0.3 g.kg(-1) body weight sodium chloride or 0.3 g.kg(-1) body weight NaHCO3-. Sixty minutes postingestion, a standardized warm-up preceded the Yo-Yo IR1. Upon completion, postexercise {[}BLa] (mmol.L-1), RPE (arbitrary units) and Yo-Yo IR1 time to fatigue (s) were recorded. Paired t-test revealed a small but significant improvement in Yo-Yo IR1 performance under the NaHCO3- condition (610 +/- 267 sec), compared to the placebo condition (556 +/- 259 sec; p=0.01; Cohen's d=0.20). {[}BLa] increased more under the NaHCO3- condition (1.6 +/- 0.7 to 17.5 +/- 5.2 mmol.L-1; p<0.001; Cohen's d=4.29), compared to the placebo condition (2.0 +/- 0.7 to 11.5 +/- 5.0 mmol.L-1; p=0.001; Cohen's d=2.66). Postexercise RPE was not significantly different between conditions. The results of this study suggest that acute NaHCO3- ingestion improves Yo-Yo IR1 performance without altering RPE, likely through an increased lactate efflux, demonstrated by increased {[}BLa].