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 NaHCO 3 on cycling time-trial performance. Furthermore, we investigated whether the ingestion time of NaHCO 3 , 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 NaHCO 3 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 NaHCO 3 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 NaHCO 3 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 NaHCO 3 ingestion has the potential to increase the overall performance time and W mean in cycling time trials. HighlightsNaHCO 3 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 NaHCO 3 ingestion has a positive effect on time and W mean during cycling time-trial performance.