Abstract
Intramuscular acidosis is a contributing factor to fatigue during high-intensity exercise. Many nutritional strategies aiming to increase intra- and extracellular buffering capacity have been investigated. Among these, supplementation of beta-alanine (~3–6.4 g/day for 4 weeks or longer), the rate-limiting factor to the intramuscular synthesis of carnosine (i.e. an intracellular buffer), has been shown to result in positive effects on exercise performance in which acidosis is a contributing factor to fatigue. Furthermore, sodium bicarbonate, sodium citrate and sodium/calcium lactate supplementation have been employed in an attempt to increase the extracellular buffering capacity. Although all attempts have increased blood bicarbonate concentrations, evidence indicates that sodium bicarbonate (0.3 g/kg body mass) is the most effective in improving high-intensity exercise performance. The evidence supporting the ergogenic effects of sodium citrate and lactate remain weak. These nutritional strategies are not without side effects, as gastrointestinal distress is often associated with the effective doses of sodium bicarbonate, sodium citrate and calcium lactate. Similarly, paresthesia (i.e. tingling sensation of the skin) is currently the only known side effect associated with beta-alanine supplementation, and it is caused by the acute elevation in plasma beta-alanine concentration after a single dose of beta-alanine. Finally, the co-supplementation of beta-alanine and sodium bicarbonate may result in additive ergogenic gains during high-intensity exercise, although studies are required to investigate this combination in a wide range of sports.
Highlights
High-intensity exercise requires maximal or near-maximal intensity efforts resulting in rapid changes in the intramuscular metabolic profile
Sodium bicarbonate, sodium citrate and sodium/calcium lactate supplementation have been employed in an attempt to increase the extracellular buffering capacity
This has led to a number of original investigations on a variety of supplements, including betaalanine, sodium bicarbonate, sodium citrate, sodium and calcium lactate, with several narrative, systematic and meta-analytic reviews published on these topics [21,22,23,24,25,26,27]
Summary
High-intensity exercise requires maximal or near-maximal intensity efforts resulting in rapid changes in the intramuscular metabolic profile. Ions for the troponin binding site, impairing the ability of the contractile machinery to effectively operate [14, 15]; (2) inhibition of phosphorylcreatine resynthesis [16]; and (3) inhibition of key enzymes of the glycolytic pathway, such as glycogen phosphorylase and phosphofructokinase [17] These effects may limit the ability of the muscle cells to cope with the high energy demand during exercise and result in a reduction in intensity and/or performance or complete cessation of exercise. The importance of the buffering systems in combating fatigue has led to increasing interest in nutritional strategies capable of increasing both intracellular and extracellular buffering capacity This has led to a number of original investigations on a variety of supplements, including betaalanine, sodium bicarbonate, sodium citrate, sodium and calcium lactate, with several narrative, systematic and meta-analytic reviews published on these topics [21,22,23,24,25,26,27]. The current review aims to summarise the available literature on all nutritional strategies aimed at increasing buffering capacity in light of more recent evidence and to highlight their underlying physiological mechanisms of action, effects on high-intensity exercise capacity and performance, and possible side effects
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
