BA is an amino acid that, together with histidine, forms the dipeptide carnosine.
Carnosine is found in muscle tissue and makes an important contribution to the maintenance of intracellular pH, which is vital for normal muscle function during intense exercise. An increased intake of BA significantly raises muscle carnosine levels.
The study, led by Jeffrey Stout, PhD from the University of Oklahoma, USA, also suggested that BA supplementation improves muscle endurance in the elderly.
"This could have importance in the prevention of falls, and the maintenance of health and independent living in elderly men and women," said Stout.
Scientists recruited 26 elderly men and women in this double-blind, randomized controlled trial, in which all the participants were given a 90-day course of BA supplementation or placebo pills.
Then, the researchers tested their fitness levels before and after the course.
In the treatment group, 67 percent of the subjects showed an improvement in their fitness levels, compared to 21.5 percent of the people receiving the placebo treatment.
"Our data suggest that 90 days of BA supplementation increases physical working capacity in elderly men and women. These findings are clinically significant, as a decrease in functional capacity to perform daily living tasks has been associated with an increase in mortality, primarily due to increased risk of falls," wrote the researchers.
The study was published in BioMed Central's open access Journal of the International Society of Sports Nutrition.