Acute effects of sodium bicarbonate ingestion on cycling time-trial performance: A systematic review and meta-analysis of randomized controlled trials

Abstract

ABSTRACT This study aimed to investigate the isolated effects of NaHCO3 on cycling time-trial performance. Furthermore, we investigated whether the ingestion time of NaHCO3, standardized or individualized based on time to peak, could be effective in improving cycling time-trial performance. A systematic review was carried out on randomized placebo-controlled studies. A random-effects meta-analysis assessed the standardized mean difference (SMD) between NaHCO3 and placebo conditions. Eighteen studies were qualitatively (systematic review) and quantitatively (meta-analysis) analysed concerning mean power output (Wmean) (n = 182) and time performance (n = 201). The reviewed studies showed a low risk of bias and homogenous results for Wmean (I2 = 0%) and performance time (I2 = 0%). Overall, when compared to placebo, the NaHCO3 ingestion improved the Wmean (SMD: 0.42; 95% CI: 0.21–0.63; P = 0.001) and performance time (SMD: 0.22; 95% CI: 0.02–0.43; P = 0.03). Similarly, the NaHCO3 ingestion using a time-to-peak strategy improved the Wmean (SMD: 0.39; 95% CI: 0.03–0.75; P = 0.04; I2 = 15%) and performance time (SMD: 0.34; 95% CI: 0.07–0.61, P = 0.01, I2 = 0%). The present findings reveal that NaHCO3 ingestion has the potential to increase the overall performance time and Wmean in cycling time trials. Highlights NaHCO3 is an effective strategy to increase cycling time-trial performance. The standardized protocol did not improve the cycling time-trial performance parameters. The individualized time-to-peak NaHCO3 ingestion has a positive effect on time and Wmean during cycling time-trial performance