Hitting the gym hard when you reach retirement age may help you preserve mobility for years to come, a new study suggests.

The study focused specifically on the benefits of resistance training to build and preserve leg strength, which is one predictor of mobility and longevity for older adults.

Researchers randomly assigned 451 adults who were 71 years old on average to follow one of three exercise routines for one year: high-intensity resistance training using weights at a gym three days a week; moderate-intensity resistance training using body weight and resistance bands once a week at a hospital and twice a week at home; and a control group who were simply encouraged to continue with whatever exercise habits they already had.

This means that heavy resistance training prevented typical age-related decline in muscle function, says the lead study author, Mads Bloch-Ibenfeldt, of the University of Copenhagen and the Institute of Sports Medicine Copenhagen at Bispebjerg Hospital in Denmark.

High-Intensity Workouts Counteracted Age-Related Decline in Muscle Function

“The trajectories were changed for leg strength, meaning that the usual age-related decline was not observed,” Bloch-Ibenfeldt says.

While the exact reasons this happened aren’t clear from the study, this bodes well for people who are trying to live longer and have more disability-free years in old age, Bloch-Ibenfeldt adds. “There is evidence that strength is associated with how long we live, and also with the risk of falling and performing everyday tasks.”

Several factors can play a role in declining muscle mass and function as we age — including loss of muscle cells and reduced activity by motor neurons in muscle fibers — and it’s possible that heavy resistance training can forestall these changes, says Peter Katzmarzyk, PhD, a professor and the associate executive director for population and public health sciences at the Pennington Biomedical Research Center in Baton Rouge, Louisiana.

“We know that muscle strength can be increased across the age span through resistance exercise programs, which occurs through an increase in muscle mass and also neuronal changes,” says Dr. Katzmarzyk, who wasn’t involved in the new study. “So it makes sense that resistance training could slow down age-related declines.”

Start Slowly, Add Intensity as You Go

One limitation of the study is that not all the participants stuck with it. A total of 82 people, or 18 percent of the participants, dropped out primarily because of lack of motivation for the workouts or because of severe illness.

Even so, the results underscore the importance of physical activity for older adults, Katzmarzyk says. Ideally, they should try to do muscle-strengthening activities at least twice a week.

“As with any activity, it is important to start slowly and build up to avoid injuries,” Katzmarzyk says. “It is also important to undertake multi-component activities, which may not only increase muscle strength but have beneficial effects on balance as well.”

The best way to approach resistance training at any age, and especially for older adults, is to start slowly and add intensity with more weight or more repetitions over time, Bloch-Ibenfeldt says. Even if people can’t manage twice a week or do as much as participants did in the study, there can still be health benefits.

“Working out, no matter how often and for how long, is better than doing nothing at all,” Bloch-Ibenfeldt says.