“Muscle is your best friend when it comes to aging and quality of life,” says Wayne Westcott, Ph.D., a professor of exercise science at Quincy College in Quincy, Mass.

But on average, we lose about 8 percent of our muscle mass each decade, starting around age 50. This can lead to fatigue, weakness, mobility problems, and increased fall and fracture risk.

Illnesses such as diabetes and certain medications, including cholesterol-lowering statins, could play a role in age-­related muscle loss. And a 2017 study of adults 35 and younger associated high daily doses of over-­the-­counter pain relievers with reduced muscle strength.

The biggest culprits are inactivity and inadequate nutrition, says Gisele Wolf-Klein, M.D., director of geriatric education for Northwell Health in Great Neck, N.Y. The remedy for muscle loss? A combination of resistance exercise and a well-balanced, protein-rich diet, Wolf-Klein says.

The Best Moves for Muscles

Westcott says that strengthening muscle ­requires resistance exercise, where muscles exert short bursts of effort against a force or weight. Research shows that just 15 to 20 minutes of resistance exercise two to three times a week can help older adults gain significant strength.

Weight machines, light hand weights, exercise bands, or your own body weight can provide resistance. ­“Focus on movements that imitate normal life activities, such as pushing or pulling a door or standing up from a sitting position,” Westcott says. These work upper- and lower-body muscle groups at the same time.

New to resistance exercise? Consider classes or one-on-one training with a certified trainer who has experience with older adults. YMCAs and Jewish Community Centers often offer senior strength classes. Or try training at home. You'll find strengthening exercises on the the National Institute on Aging website.

“Ease into it with light resistance and a few exercises,” says Brian Clark, Ph.D., executive director of the Ohio Musculoskeletal and Neurological Institute at Ohio University. “You can gradually increase the volume and intensity.” 

Eating for Muscle Strength

A protein-rich diet goes hand in hand with exercise, says Kelsey Mangano, Ph.D., nutri­tion program director at the University of Massachusetts Lowell.

Women and men 51 and older, who absorb nutrients less efficiently than younger people do, should strive for at least 46 and 56 grams of protein a day, respectively. For the sake of comparison, a 4-ounce chicken breast has about 35 grams of protein, and a half-cup of kidney beans contains about 11 grams.

When possible, opt for whole, unprocessed protein sources, such as lean meat and seafood. Include nuts, seeds, and beans, too. A study conducted by Mangano and colleagues found that protein from plant-based foods may be as beneficial for muscle in older adults as protein from meat.

If you find yourself getting full quickly, try spacing your protein consumption out over the day, Mangano suggests. That could have other benefits: A study published in 2017 in the American Journal of Clinical Nutrition found that consuming an equal amount of protein at all three daily meals may be linked to greater muscle strength in people 67 and older. 

Can Hormones Help?

You might have heard that taking hormones can help you maintain muscle. One analysis found that testosterone replacement therapy (TRT) could have beneficial effects on muscle mass and strength in men younger than 50 with low testosterone.

Potential TRT risks in older men include excess red blood cells and worsening prostate cancer and sleep apnea. The FDA has warned that TRT may increase heart attack and stroke risks.

Estrogen therapy (ET) boosts muscle strength in post-menopausal women, but long-term ET increases the risk of endometrial cancer and estrogen/progestin therapy (EPT) is linked to a higher breast cancer risk. Oral hormone therapy is also associated with an increased risk of stroke. So if you’re considering hormone therapy, be sure to discuss its potential risks and benefits with your doctor. 

Editor's Note: This article also appeared in the January 2018 issue of Consumer Reports on Health.