Aerobic exercise is the type of workout most people think of when they’re trying to keep fit—and with good reason. But research shows it’s also vital to tend to your muscles with strength training—especially if you’re 50 and up.
Most physiological functions begin to slow down when people are in their mid-20s. After age 50, muscle mass declines approximately 10 percent every 10 years. As muscles atrophy, the percentage of body fat increases relative to muscle tissue. By age 70, the body is composed of comparatively more fat, and muscles are considerably weaker than they once were.
This process of losing muscle presents a host of potential problems. Muscles provide vital support for a large portion of the body’s weight. As muscles shrink and weaken with age, the burden of supporting weight shifts onto bones and joints, which can lead to osteoarthritis—the breakdown of cartilage between joints.
Muscles also help to prevent falls by maintaining proper balance and coordination. The loss of bone that starts at around age 30 increases the risk of fractures. But bones do not just break on their own. It is the loss of muscle combined with poor balance and coordination that causes the fall that results in a broken bone.
While insufficient muscle strength can lead to injury, it can also make it more difficult for people to recover from injury or illness. Older adults who lose a lot of muscle mass become frail, which can lead to a cycle of disability, low physical activity, weakness and poor nutrition.
Strength training: Why it’s good
Strength training (also called weight training or resistance training) is any exercise that causes your muscles to contract against a resistance. By this definition, walking is a form of strength training. When you walk, you are carrying your own weight against the force of gravity, which means you are using your body for resistance. Consequently, in addition to its aerobic benefits, walking helps preserve some degree of muscle strength.
But to improve muscle and bone strength over and above what you can achieve by walking, you’ll need to add strength-training exercises to your routine. Older adults need this extra push to help make up for the muscle and bone mass that is lost naturally with age and to help prevent or manage specific conditions such as osteoporosis, arthritis and poor balance.
Studies have shown that strength training results in substantial improvements in insulin sensitivity and glucose metabolism, which lower diabetes risk. In addition, strength training improves cholesterol levels, which helps prevent cardiovascular disease. Some researchers have also reported that this type of exercise can help reduce abdominal fat, but others have not found such a benefit.
First, get your doctor’s OK. According to the American College of Sports Medicine (ACSM) your doctor’s input is critical if you have any orthopedic issues, such as osteoporosis or knee surgery, or other medical conditions that could be affected by strength training.
Once you get the all clear, there’s no need to buy expensive equipment or join a gym. You can get excellent results using simple calisthenic exercises, such as leg lifts or push-ups, and exercise bands, which can be purchased at a local sports store. Good news, too, if you’re a gardener or yoga devotee: Heavy gardening (involving digging or shoveling) and yoga count as strength-training exercise.
How often should you do strength training? Current guidelines from the U.S. Department of Health & Human Services recommend that older adults who are generally fit and have no limiting health conditions set aside two days a week for strengthening the major muscle groups—legs, hips, chest, back, abdomen, shoulders and arms. You can accomplish this by lifting weights, working with resistance bands, and doing exercises that use your body weight for resistance such as push-ups and sit-ups. If you haven’t been exercising, start with one set of eight to 12 repetitions. For even greater benefit, work your way up to two or three sets.
To reduce the risk of injuring your muscles, the ACSM recommends consulting a trained exercise professional who has experience working with older adults. He or she can also provide guidance on how and when to vary your strength-building routine for optimal benefits.