Sex-dependent responses to acute sodium bicarbonate different dose treatment: A randomized double-blind crossover study.

Objectives: This study quantified blood bicarbonate (HCO) kinetics and gastrointestinal upset to determine the gender-related ergogenic potential of sodium bicarbonate (0.15-, 0.25- and 0.35 g·kg) in high intensity functional training.

Design: Double-blind randomized placebo-controlled crossover.

Methods: Thirty female and male athletes performed two bouts of the Wingate Anaerobic Test (WAnT and WAnT) interspaced with two 3-min bouts of Wall Balls and Burpees 120min after ingestion of three sodium bicarbonate doses. Blood HCO was determined pre-ingestion, after supplementation and before/post exercise. Gastrointestinal upset was evaluated 120min post-ingestion. Control (CTRL) measurements were performed.

Results: There were significant gender×treatment interactions for: changes in blood HCO at 60min post-ingestion (p=0.014; η=0.104; at 0.15g·kg males experienced higher increase than females); peak power (p=0.015; η=0.103) and average power (p=0.005; η=0.124) during WAnT, and changes in peak power between the Wingate Anaerobic Test bouts (p=0.049; η=0.081). Sodium bicarbonate compared to PLA had no significant impact on Wall Balls and Burpees performance. The dose of 0.35g·kg resulted in higher less severe gastrointestinal symptoms compared to CTRL and 0.15g·kg (p=0.001; W=0.178); and higher total gastrointestinal upset compared to CTRL, PLA and 0.15g·kg (p<0.001; W=0.323).

Conclusions: There were dose- and gender-related differences in extracellular buffering capacity and ergogenic potential of sodium bicarbonate. The study suggested a detrimental impact of gastrointestinal upset on performance.