Xiaolin Yang, Qian Yang, Zihong He, Dapeng Bao, Xun Jiang, Lars McNaughton
SB supplementation increased overall WEP across repeated 3MTs, although the ergogenic effects were more evident during the first bout. Divided ingestion of 0.4 g·kg- 1 body mass may provide the most favorable balance between ergogenic benefit and gastrointestinal tolerance.
PURPOSE: This study compared four sodium bicarbonate (SB) supplementation strategies differing in dose and dosing pattern on end-test power (EP), work performed above EP (WEP), and blood acid-base responses during two 3-min all-out cycling tests (3MTs) separated by 70 min.
METHODS: Sixteen trained men completed a randomized crossover study involving four SB conditions: single-dose moderate-SB (SM-SB), multiple-dose moderate-SB (MM-SB), single-dose higher-SB (SH-SB), and multiple-dose higher-SB (MH-SB), and placebo (PLA). The SB conditions comprised 0.3-0.4 g·kg⁻¹ body mass administered as a single or multiple dose. Ninety minutes after supplementation, participants performed two 3MTs separated by 70 min, with blood variables measured before and after each bout and during recovery.
RESULTS: Overall WEP showed significant main effects of supplementation condition (F = 4.10, ηp² = 0.11, P < 0.05) and time (F = 13.50, ηp² = 0.09, P < 0.05), with no significant condition × time interaction. During 3MT1, WEP was higher with SM-SB and MH-SB than PLA (~ 17.9% and ~ 18.6%, respectively; P < 0.05), with a significant condition main effect. Whereas during 3MT2, WEP was higher with SH-SB than PLA (~ 15.7%, P < 0.05), despite no significant condition main effect. EP showed no supplementation condition × time interaction (F = 0.60, ηp² = 0.02, P > 0.05) or supplementation condition main effect, but differed between 3MT1 and 3MT2 (F = 11.07, ηp² = 0.08, P < 0.05). A significant supplementation condition × time interaction was observed for blood [HCO3⁻] (P < 0.05). All SB conditions resulted in higher [HCO3⁻] than PLA before both 3MTs (P < 0.05), with no differences among SB conditions. Lactate also showed a significant supplementation condition × time interaction (F = 1.82, ηp² = 0.08, P < 0.05), with higher concentrations immediately after both 3MTs in all SB conditions than PLA (P < 0.05).
CONCLUSION: SB supplementation increased overall WEP across repeated 3MTs, although the ergogenic effects were more evident during the first bout. Divided ingestion of 0.4 g·kg- 1 body mass may provide the most favorable balance between ergogenic benefit and gastrointestinal tolerance.