The Journal of the International Society of Sports Nutrition published a study online reporting the positive impact that amino acid arginine and antioxidants had on physical capacity in men over 50.


UCLA researcher Zhaoping Li and associates placed a group of cyclists between 50 and 73 years into two groups, one that received a supplement consisting of several amino acids (arginine, citrulline, taurine, alpha-lipoic acid, vitamin C, vitamin E, and folic acid mixed with water.  The participant’s blood was sampled at the study’s beginning, after 7 and 21 days, and their physical performance were measured by testing on a stationary bicycle.


Those who received arginine experienced a 16.7 percent increase in exercise capacity. It remained elevated in the group receiving this amino acid, while remaining unchanged in the group that did not receive it.


Nitric oxide, is a chemical the body produces that helps the arteries to relax.  Its level declines over time, and the smaller amounts may play a role in the development of heart disease. Arginine stimulates nitric oxide production, and the antioxidants in the formula are deactivated by free radicals.


“The loss of exercise capacity with age often results in a reduction in physical fitness and more rapid senescence,” noted lead researcher Zhaoping Li of the University of California, Los Angeles David Geffen School of Medicine. “A dietary supplement that increases exercise capacity might help to preserve physical fitness by optimizing performance and improving general health and well being in older people.”


“We’ve demonstrated a 16.7% increase in anaerobic threshold,” Dr Li stated. “This indicates a potential role of arginine and antioxidant supplementation in improving exercise performance in elderly.”