“This shows that healthy older people can certainly respond to resistance training, that their muscles are still plastic,” said Tommy Lundberg, an exercise researcher at the Karolinska Institute in Sweden, who was not involved in the study.
Lundberg, author of the new book, “The Physiology of Resistance Training,” said research shows it’s never too late for older people to start lifting weights. “They can increase both the size of your muscles and your strength,” he said.
More than anything, the study implies that our perceptions of what is physically possible in old age may also need updating.
“It is often assumed that older people, or, say, people over 80, are less likely to gain muscle mass and strength,” said Luc van Loon, professor of human biology at Maastricht University, and lead author of the new study.
This idea took hold in part because the oldest ones were rarely studied. Previous research on weight training often limited the age of volunteers to about 75, out of concern that older people would not be able to withstand the training or that their muscles would not respond if they were able to lift weight.
But van Loon and his colleagues were not convinced. “Muscle tissue is constantly renewed as we live,” he said, so why shouldn’t an octogenarian’s muscles strengthen and grow as well as those of a 65-year-old?
To investigate that idea, he and his co-authors recruited 29 healthy older men and women. The study was made up of two groups. The “younger elders” included 17 people between 65 and 75 years old. Participants in the “older seniors” group were at least 85 years old. They all lived independently and did not suffer from debilitating illnesses.
Neither had trained with weights regularly before.
Get stronger at any age
The researchers measured everyone’s current strength and muscle mass and then introduced them to weight training, with a basic full-body resistance routine using gym machines like the lat pulldown and leg extension. The volunteers lifted weights three times a week for 12 weeks, in supervised sessions, using weights adjusted to up to 80 percent of their total strength.
This program is more intense than some people might expect older people to tolerate. But the volunteers “loved participating in this intervention,” said Gabriel Nasri Marzuca-Nassr, an associate professor at the University of La Frontera in Chile, who led the new study. Attendance was high and injuries rare.
And both the “younger seniors” and the “older seniors” groups responded powerfully to exercise, somewhat surprising the researchers. Before the study began, Marzuca-Nassr said, he and his co-authors expected older men and women to gain strength and mass, but to a lesser extent than among people ages 65 to 75.
However, after three months, people ages 85 and older had packed on more strength and mass, relatively speaking, than the younger group, adding an average of 11 percent to muscle mass and 46 percent to strength, compared to 10 percent more muscle and 38 percent more strength among the youngest volunteers.
The older men and women also improved their scores on a test of their ability to get up from a chair and move around by about 13 percent, compared with 8 percent for the younger groups.
The researchers believe the older group’s greater relative gains were due, in part, to having had an extra decade of decline in muscle size and strength compared to younger lifters. They started from a lower base.
The results convincingly show that “it’s never too late to start training,” said Michael Roberts, a professor of kinesiology at Auburn University in Alabama, who has studied resistance exercise extensively.
The improved mobility of the older age group was especially encouraging, he added, because “loss of physical function is ultimately what defines frailty.”
The results have caveats. The study was small and lasted only three months. Additionally, the training was supervised, with people’s lifting form and loads monitored and adjusted as necessary, a level of attention that could be difficult for everyday people to replicate.
The study is also not intended to give any of us carte blanche to skip weight training now in anticipation of starting in retirement. “It’s better to start at a younger age,” Marzuca-Nassr said, “and continue throughout life.”
Perhaps most importantly, the older men and women who participated in the study were healthy for their age and had few obvious physical limitations. It may be unrealistic for some older people with serious illnesses or disabilities to begin lifting.
If you’re concerned about your readiness for weight training, Marzuca-Nassr recommended, talk to your doctor.
Anyone over 60 who is interested in starting a new weight-lifting or other exercise routine should probably consult with their doctor first and then look into training programs at a gym or community center designed specifically for seniors. Costs are often covered by Medicare or other insurance.
However, the key takeaway from the study is that there appears to be no age limit or strict brakes on our bodies’ ability to adapt and improve, said study co-author van Loon. “You’re never too old to start exercising.”
Do you have any questions about fitness? Email TuMove@washpost.com And we may answer your question in a future column.
