Seeing your 10k time worsen from a 20-something best of 43 minutes to a retirement-age 56 minutes? Probably a bummer. Getting so frail that activities like lifting groceries onto the counter become impossible? Definitely a major bummer. And sarcopenia, the age-related decline in muscle mass and function, contributes to both. Researchers don't know exactly what causes the deterioration and how much is inherent as opposed to caused by inactivity, but typically people begin to lose about 1 percent of muscle mass per year in their 40s. With each advancing decade, the rate accelerates; by the 70s, the muscle loss can be 15 percent a decade. Luckily, there are ways to prevent it.
The tool that everyone agrees works to shore up muscles: an exercise habit, preferably a lifelong one. That means an aerobic fitness routine—like a 30-minute walk every day—to help keep muscle tissue healthy. And it means a basic strength-training program. (It should be progressive, which means adding more weight when you can tolerate it.) Strength training that builds muscle helps keep older folks stable, surefooted, and strong enough to do basic things like get out of a chair. Indeed, some data suggest that men who lift weights a few times a week in their 50s and 60s can not only slow the loss of muscle mass but actually halt it. Even folks in their 90s have been able to build back muscle with proper training, says Robert Wolfe, a professor of geriatrics at the University of Arkansas.
Some researchers are investigating whether proper nutrition also can stave off muscle loss. Insufficient protein, especially if accompanied by insufficient calories in general, can play a role in sarcopenia. The advice of Douglas Paddon-Jones, director of exercise studies for the General Clinical Research Center at the University of Texas Medical Branch in Galveston, is to eat small amounts of complete protein throughout the day. In other words, have a small amount of foods rich in complete protein, like fish, chicken, beef, or dairy, at every meal. (Vegetarians can turn to soy or combinations of amino acid sources, like rice, beans, and nuts.) Keep each of those servings to 4 ounces—about the size of a deck of cards.