Journal Title (Medline/Pubmed accepted abbreviation): Med. Sci. Sports Exerc.
Page numbers: 1545-1551
Background: Carnosine is a molecule found in muscle that is made of two amino acids- β-alanine and histidine. It acts as an intracellular buffer, thereby controlling intra-cellular pH and preserving healthy function of the cell during the stress of exercise. Habitual supplementation with β-alanine can increase muscle carnosine concentrations.
Bicarbonate is a natural buffering system in the blood, and also plays a large role in buffering pH within the cell. It is thought that, during exercise, a rise in lactate and protons (H+) can accumulate in muscle and can contribute to muscular fatigue. Buffers can help remove these molecules and allow for greater work to be done.
Hypothesis: The combination of habitual β-alanine supplementation and one-time bicarbonate supplementation will increase the performance of trained athletes on a maximal cycling trail lasting 4 min.
Subjects: Highly trained male cyclists (n = 14), age 25.4 ± 7.2 y
Experimental design: double-blinded, placebo-controlled, randomized, repeated measures
β-alanine- 65 mg/kg body weight per day, divided into 4 doses, taken with meals, or a placebo- dextrose (sugar) in the same dose
Sodium bicarbonate (NaHCO3)- 0.3 g/kg body weight taken with 10 mL/kg of water, or a placebo, were administered after the period of β-alanine supplementation.
Protocol: The participants were first familiarized with the exercise equipment (a stationary bicycle) and evaluated for oxygen capacity (VO2max), maximum heart rate, and maximum aerobic output. At a subsequent visit to the laboratory, they completed baseline testing. Performance testing involved a 9 min warm-up followed by 4 min of maximum output. Their peak and average power were monitored as well as total work done. Blood samples were collected before and after exercise. They then took β-alanine (or the placebo) for 4 weeks. During the 4 wks of β-alanine supplementation, in order to control training, the participants were asked to complete short duration, high intensity cycling sprints twice per week according to a specific protocol. They kept a diary of all exercise. During the 5th week, they reported to the laboratory on 2 occasions separated by 2-4 days. They ingested either NaHCO3 or a placebo in 6 doses over the span of 60 min. After a 30 min rest, they completed the same performance testing protocol as at baseline. Blood samples were acquired before and after NaHCO3 ingestion and after exercise.