Exercise is important for people of all ages, but may be especially crucial for those who are turning 65 or older. Staying physically active - even if it's just through daily walks in the park - can go a long way toward improving one's health and mood.

Lead author Benjamin F. Miller and his team from the Department of Health and Exercise Science at Colorado State University recruited 16 participants over the age of 37. These individuals were instructed to work out on treadmills for 45 minutes three times a week over a six-week period. After each bout of exercise, they either drank a protein or a carbohydrate drink.

At the end of the study, the researchers took muscle samples from each of the subjects. They measured the amount of new proteins, DNA and membranes in each specimen, and found that endurance exercise induces positive changes in the structure of skeletal muscle. This could be especially important for older people.

"If you want to age gracefully, this study shows that proteins taken after exercise keep your muscles strong and fit," said FASEB editor-in-chief Gerald Weissmann.