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Effects of beta-alanine and sodium bicarbonate supplementation on CrossFit performance

Grant number: 19/22249-7
Support type:Scholarships in Brazil - Master
Effective date (Start): February 01, 2021
Effective date (End): January 31, 2023
Field of knowledge:Health Sciences - Nutrition
Principal Investigator:Bryan Saunders
Grantee:André Guedes da Silva
Home Institution: Faculdade de Medicina (FM). Universidade de São Paulo (USP). São Paulo , SP, Brazil

Abstract

Beta-alanine is an amino acid which, when bound to histidine, forms a dipeptide called carnosine (²-alanyl-L-Histidine). Beta-alanine has strong evidence as an ergogenic aid, and it is well established that through the increase of muscle carnosine content, intracellular H+ buffering capacity is increased, due to the acid dissociation constant of its imidazole ring (pKa = 6.83), which makes carnosine a great physiological buffer to maintain intramuscular pH. Another substance with large relevance for buffering capacity is sodium bicarbonate. Increased circulating bicarbonate improves intramuscular pH regulation via an increased efflux of H+ protons via monocarboxylate transporters (MCT's) from the muscle cell to the blood. CrossFit is a high intensity sports modality composed of varied functional movements that has enormous popularity Since there is evidence to support the use of beta-alanine and sodium bicarbonate supplementation to enhance performance during high-intensity exercises by raising intracellular and extracellular buffering capacity, this may also improve CrossFit performance. The present study will investigate the effect of isolated and combined beta-alanine and sodium bicarbonate supplementation on CrossFit performance. Twenty-four healthy males between 18 and 45 years old, with at least one-year CrossFit experience a minimum of 3 times a week, will be recruited to this double-blind and placebo-controlled study and perform a baseline maximal oxygen uptake test, two familiarizations of the CrossFit protocol and a pre-supplementation session. Participants will then be randomly allocated into one of two groups to supplement with 6.4 g/day beta-alanine or placebo (maltodextrin) for 4 weeks (2 x 800 mg, 4 times per day on 3 - 4 hours intervals). After 4 weeks of beta-alanine or placebo supplementation, participants will perform two sessions following either acute sodium bicarbonate or maltodextrin (0,3 g/kg one hour before exercise) supplementation resulting in the following subgroups: BA+SB, BA+PLA, PLA+SB e PLA+PLA. The exercise protocol will be composed of the CrossFit WODS Cindy followed by Fight Gone Bad WOD Blood samples will be collected and analysed for lactate, pH, and bicarbonate. Muscle biopsies from the vastus lateralis and deltoid muscles well be taken pre- and post-beta-alanine supplementation to determine muscle carnosine content. (AU)