Effect of sodium bicarbonate contribution on energy metabolism during exercise: a systematic review and meta-analysis

BACKGROUND: The effects of sodium bicarbonate (NaHCO(3)) on anaerobic and aerobic capacity are commonly acknowledged as unclear due to the contrasting evidence thus, the present study analyzes the contribution of NaHCO(3) to energy metabolism during exercise. METHODS: Following a search through five databases, 17 studies were found to meet the inclusion criteria. Meta-analyses of standardized mean differences (SMDs) were performed using a random-effects model to determine the effects of NaHCO(3) supplementation on energy metabolism. Subgroup meta-analyses were conducted for the anaerobic-based exercise (assessed by changes in pH, bicarbonate ion [HCO(3)(−)], base excess [BE] and blood lactate [BLa]) vs. aerobic-based exercise (assessed by changes in oxygen uptake [VO(2)], carbon dioxide production [VCO(2)], partial pressure of oxygen [PO(2)] and partial pressure of carbon dioxide [PCO(2)]). RESULTS: The meta-analysis indicated that NaHCO(3) ingestion improves pH (SMD = 1.38, 95% CI: 0.97 to 1.79, P < 0.001; I(2) = 69%), HCO(3)(−) (SMD = 1.63, 95% CI: 1.10 to 2.17, P < 0.001; I(2) = 80%), BE (SMD = 1.67, 95% CI: 1.16 to 2.19, P < 0.001, I(2) = 77%), BLa (SMD = 0.72, 95% CI: 0.34 to 1.11, P < 0.001, I(2) = 68%) and PCO(2) (SMD = 0.51, 95% CI: 0.13 to 0.90, P = 0.009, I(2) = 0%) but there were no differences between VO(2), VCO(2) and PO(2) compared with the placebo condition. CONCLUSIONS: This meta-analysis has found that the anaerobic metabolism system (AnMS), especially the glycolytic but not the oxidative system during exercise is affected by ingestion of NaHCO(3). The ideal way is to ingest it is in a gelatin capsule in the acute mode and to use a dose of 0.3 g•kg(− 1) body mass of NaHCO(3) 90 min before the exercise in which energy is supplied by the glycolytic system.