Losing weight later in life may depend more on lifting weights than walking, according to Wake Forest University researchers.
The findings appear in the November issue of the journal Obesity.
Researchers conducted an 18-month study of 249 adults in their 60s who were either overweight or obese.
They found that combining weight-machine workouts with restricting calories contributed to not only less muscle loss, but significant fat loss. That’s when compared with weight loss alone.
Participants who combined a low-calorie diet with weight lifting lost on average 17 pounds, compared with 16 pounds through a low-calorie diet and walking and 10 pounds via just a low-calorie diet.
Meanwhile, muscle mass loss was greatest with diet plus walking (about 4 pounds), compared with diet alone or diet plus weight training (each about 2 pounds).
“A lot of older adults will walk as their exercise of choice,” said Kristen Beavers, the study’s lead author and an assistant professor of health and exercise science at Wake Forest University.
“But this research shows that if you’re worried about losing muscle, weight training can be the better option.”
Losing weight is generally recommended for those with obesity, but preserving muscle — while losing fat — is particularly important for older adults in order to maximize functional benefit, Beavers said.
“Surprisingly, we found that cardio workouts may actually cause older adults with obesity to lose more lean mass than dieting alone.”
Loss of lean mass could have important consequences given the high risk of physical disability among the growing population of older adults.
Another finding was that while loss of fat was associated with faster walking speed, loss of muscle was associated with reduced knee strength.
These results may be even more important for older adults who gain and lose weight with frequency.
Seniors typically don’t regain muscle — they regain fat mass — which is “all the more reason for older adults to try and preserve muscle mass during weight loss,” Beavers said.
The research was funded by a grant from the National Institutes of Health/National Heart, Lung and Blood Institute. Partial support also came from grants by the National Institute on Aging.
This story has been edited to clarify that Kristen Beavers is an assistant professor at Wake Forest University.