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

This study investigated the effect of sodium bicarbonate (NaHCO3-) ingestion on the Yo-Yo Intermittent Recovery Test 1 (IR1). We tested the hypotheses that acute ingestion of NaHCO3- would increase blood lactate concentrations [BLa], enhance performance and reduce ratings of perceived exertion in the Yo-Yo IR1. Eight recreationally active males (N=8, age 26±4 years, height 178±6 cm, body mass 82±10 kg) participated in the Yo-Yo IR1 on two separate occasions, separated by one week, in a randomized crossover design. Following familiarization, during seated rest, participants’ pre-test [BLa] were taken and participants then consumed either a placebo of 0.3 g·kg-1 body weight sodium chloride (NaCl), or 0.3 g·kg-1 body weight NaHCO3-. Sixty minutes post-ingestion, a standardized warm-up preceded the Yo-Yo IR1. Upon completion, post-exercise [BLa] (mmol·l-1), ratings of perceived exertion (RPE; arbitrary units) and Yo-Yo IR1 time to fatigue (s) were recorded. T-test revealed a small, but significantly improvement in Yo-Yo IR1 performance under the NaHCO3- condition (610± 267s), compared to placebo condition (556±259 s: p=0.01; Cohen’s d=0.20). Blood lactate 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). Post-exercise RPE was not significantly different between conditions. 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].