Effects of buffering agents on high-intensity exercise performance and capacity

High-intensity exercise results in hydrogen ion accumulation, which can have a deleterious effect on muscle function, and thus exercise tolerance. Buffering agents are commonly used to enhance exercise performance and capacity. Two such agents, β-alanine and sodium bicarbonate, increase intracellular and extracellular buffering capacity, which could contribute to an improved performance and capacity during exercise limited by increasing acidosis. Despite this, studies on the ergogenic effects of β-alanine are still in their infancy, and research on sodium bicarbonate remains equivocal. The aim of this thesis was to investigate the separate and combined effects of β-alanine and sodium bicarbonate on high-intensity exercise performance and capacity using various exercise modalities. The CCT110%, a cycling capacity test, was shown to be reliable (Chapter 4A), and subsequently employed to investigate the effect of sodium bicarbonate (Chapter 4B), β-alanine and co-supplementation of the two (Chapter 4C). Sodium bicarbonate supplementation was shown to improve total work done during the CCT110% (+4.8%), only when those experiencing gastrointestinal discomfort were removed from analyses, as was β-alanine (+14.6%); co-supplementation of the two did not confer any further benefits above β-alanine alone. Neither sodium bicarbonate (Chapter 5A) nor β-alanine or co-supplementation of the two (Chapter 5B) improved 5 x 6 s repeated running sprints (all P > 0.05)