Lactic acid, which causes achy muscles during hard exercise, builds up more easily with age. Researchers thought the amino acid beta-alanine could increase maximum exercise capacity in older adults by helping to stabilize acidity levels.
In the study, 26 men and women, aged 55 to 92, took 800 mg of beta-alanine three times per day or a placebo. After three months, doctors gave a maximum-effort test and found that those in the beta-alanine group could exercise 29 percent longer at the point of fatigue than those in the placebo group. Doctors said beta-alanine could help prevent falls and keep older adults healthier and living independently longer.
Journal of the International Society of Sports Nutrition; 2008, Vol. 5, No. 1, 21t.