Calorie Reduction + Exercise = Better Muscle Function in Older Adults

Newswise — San Diego (August 28, 2017)—Improved muscle performance starts with better mitochondrial function. Older adults who are overweight may improve their muscle function with a weight loss program that combines exercise and calorie reduction, according to researchers from Florida Hospital, in Orlando, Fla., who present their findings today at the American Physiological Society’s Physiological Bioenergetics: Mitochondria from Bench to Bedside conference in San Diego.

The researchers studied three groups of obese seniors (average age: 70) over the course of six months:

• One group followed a reduced-calorie diet to lose weight.
• A second group combined calorie restriction with a supervised exercise program.
• A control group attended health education classes but did not follow any specific diet or exercise program.

The research team took samples of muscle fibers from all volunteers before and after the trial period to measure the mitochondria’s ability to use oxygen and provide the cells with energy (mitochondrial respiratory capacity). Mitochondrial respiratory capacity typically decreases with age as some people become less active and gain weight. “Increased mitochondrial capacity is desired as it translates to greater metabolic and muscular functions,” wrote Giovanna Distefano, PhD, first author on the study.

The researchers found no change in mitochondrial respiration rate in the control and calorie-restricted groups. The exercise and diet group, however, demonstrated improved mitochondrial respiration rates and a higher exercise capacity. These results suggest that “the addition of exercise training to a calorie restriction-induced weight loss program is essential to promote improvements in mitochondrial capacity,” Distefano wrote.

Giovanna Distefano, PhD, will present “Exercise combined with calorie restriction-induced weight loss, but not weight loss alone, improves mitochondrial respiratory capacity in skeletal muscle of older obese subjects” at a poster session on Monday, August 28, from 5 to 7 p.m. in the U.S. Grant Hotel.

NOTE TO JOURNALISTS: The Physiological Bioenergetics: Mitochondria from Bench to Bedside conference will be held in San Diego, August 27–30, 2017. Read the full program. To schedule an interview with the conference organizers or presenters, contact the APS Communications Office or call 301-634-7209. Find more research highlights in the APS Press Room.