Effect of acute sodium bicarbonate supplementation on performance, subjective perception of effort and gastrointestinal discomfort in CrossFit® male practitioners

Abstract

Introduction: CrossFit® is a training methodology defined as "functional movements, high intensity, constantly varied". In sports one of the resources used to increase performance are dietary supplements. Sodium bicarbonate (NaHCO₃) acts as a buffer at the blood level, playing an important role in maintaining intra- and extracellular pH during high intensity and short duration exercise. Thus, the aim of this study was to evaluate the effect of acute NaHCO₃ supplementation on performance, subjective perceived exertion (PSE) and gastrointestinal discomfort in CrossFit® practitioners. Materials and Methods: This is an acute, randomized, double-blind, parallel, placebo-controlled clinical study with non-probabilistic sampling for convenience. 6 men practicing CrossFit®️ were included where they performed a Benchmark (grace) in two non-consecutive days, in the first no supplementation was used and in the second they received 1.2 g·kg-1 of maltodextrin with 0.3 g·kg-1 of NaHCO₃ for the bicarbonate group or 2 g of NaCl for the placebo group. Performance, PSE by the adapted Borg scale, and symptoms of gastrointestinal discomfort were assessed at the end of training. Results: There was an increase in performance after the intervention in both experimental groups. There was no change in PSE when comparing the groups. No participant reported gastrointestinal discomfort after supplementation. Conclusion: The protocol used was effective in avoiding adverse gastrointestinal effects, but acute supplementation of 0.3 g·kg-1 NaHCO₃ was not effective in increasing performance and altering PSE in men practicing a Benchmark (grace) in CrossFit®.