•  
  •  
 

SODIUM BICARBONATE IMPROVES REAPEAT SPRINT ABILITY IN THE HEAT WITHOUT ALTERING PHYSIOLOGICAL OR PERCEPTUAL STRAIN

Abstract

Sodium bicarbonate (SB), commonly known as baking soda, is a readily available supplement that improves performance in repeated sprint ability (RSA) via buffering of hydrogen ions. In hot environments, RSA has been shown to decrease potentially due to hyperthermia rather than metabolic acidosis. PURPOSE: To investigate the effects of SB supplementation on performance, physiological, and perceptual responses to RSA in the heat. METHODS: In a randomized, crossover, double-blind design, 10 endurance athletes (4 female) consumed 0.2 g/kg body weight of SB or placebo 1 hr prior to exercise. Participants underwent a 22-min warm-up followed by 4 sets of 5 x 6-sec maximal cycling sprints at a resistance of 7.5% of body weight in a hot environment (40 °C, 20% RH). Each set of 5 sprints was followed by a 24-sec passive recovery period, with 5 min rest between sets. Peak power (PP), average power (AP), and heart rate (HR) were recorded for each sprint. Percent decrement score was calculated for PP (%PP) and AP (%AP) in each set. Peak respiratory exchange ratio (RER) was recorded for each set. Blood lactate was measured pre-exercise, post warm-up, and after the 2nd and 4th set. Peak core temperature (Tc), rating of perceived exertion (RPE), and thermal strain (TS) were also recorded throughout. All variables were analyzed via two-way repeated measures ANOVAs using an alpha level of p < 0.05. RESULTS: SB significantly increased PP by 3.4% (Placebo: 611±175 W, SB: 631±169 W; p=0.02) and AP by 2.3% (552±155 W, 565±147 W; p=0.03). Peak RER was greater in the SB condition by 4% (1.35±0.18, 1.40±0.19; p=0.03). Blood lactate showed an interaction effect (p=0.006) with no significant differences between conditions pre-exercise (1.9±1.0 mmol/L, 1.8±0.8 mmol/L; p=0.99) or post warm-up (4.2±1.8 mmol/L, 4.1±1.5 mmol/L; p=0.99) but higher values in the SB condition after the 2nd (10.9±4.2 mmol/L, 12.8±4.0 mmol/L; p=0.04) and the 4th (11.1±5 mmol/L, 14.1±3.9 mmol/L; p=0.0006) set. No significant differences were observed between conditions for %PP, %AP, Tc, HR, RPE, or TS (p>0.05). CONCLUSION: SB improved RSA in the heat in endurance athletes without exacerbating physiological or perceived strain. These findings suggest that RSA improvements from SB supplementation were due to enhanced buffering capacity rather than altered thermoregulation.

This document is currently not available here.

Share

COinS