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

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 (W-mean) (n = 182) and time performance (n = 201). The reviewed studies showed a low risk of bias and homogenous results for W-mean (I-2 = 0%) and performance time (I-2 = 0%). Overall, when compared to placebo, the NaHCO3 ingestion improved the W-mean (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 W-mean (SMD: 0.39; 95% CI: 0.03-0.75; P = 0.04; I-2 = 15%) and performance time (SMD: 0.34; 95% CI: 0.07-0.61, P = 0.01, I-2 = 0%). The present findings reveal that NaHCO3 ingestion has the potential to increase the overall performance time and W-mean in cycling time trials.

Automated summary

This study investigates the isolated effects of NaHCO3 on cycling time-trial performance, and explores whether the timing of NaHCO3 ingestion can be optimized to improve performance. The findings reveal that NaHCO3 ingestion significantly enhances mean power output and performance time in cycling time trials.