May 17, 2017
By Gene Emery
(Reuters Health) - For obese people over age 64, the combination of aerobic exercise and weight training is better for improving physical functioning than either form of exercise alone, a new study concludes.
Each type of exercise and a combination of the two produced 9 percent reductions in body weight over six months. But the combination provided the best mix of protection against muscle and bone loss with improved aerobic capacity.
Aerobic exercise and weight training "have additive effects in improving your physical function," chief author Dr. Dennis Villareal of the Baylor College of Medicine and the DeBakey VA Medical Center in Houston told Reuters Health by phone. "Overall the patient feels it, and we were able to document that objectively."
The findings in the New England Journal of Medicine May 17 have broad significance because one third of older adults in the United States are obese, with all the health risks that come with being very overweight. Yet there is concern that weight loss might make them even more frail because bone and muscle might be lost as well.
The results suggest that fear is unfounded.
One hundred sixty volunteers from New Mexico with a body mass index of 30 or higher and no history of regular exercise were enrolled in the study. Of this group, 141 participants, mostly white well-educated women, completed it. To assess physical performance, the Villareal team used a 37-point scale, where higher numbers indicated better physical performance.
The volunteers who participated in 60-minute aerobic or weight training sessions three times a week for six months showed increases in performance of 14 percent, improving by 3.9 points on that 37-point scale.
The volunteers who got both aerobic and strength training in longer sessions that lasted 75 to 90 minutes showed an improvement of 5.5 points, or 21 percent.
"In essence, the combined group exercised more than the aerobic group alone and the resistance group alone," said Dr. Felipe Lobelo of the Emory University - Rollins School of Public Health in Atlanta, who was not involved in the study. "So in terms of the volume of energy expenditure, that group did more. So to me it's not surprising to me that they got more benefits."
But Villareal said there was concern that the two types of exercise, if combined in a single session, might interfere with each other so the exercise time in the combined group was longer.
"Otherwise they will be doing less resistance and less aerobic as compared to the resistance group and the aerobic group," he said. "That's not a fair comparison."
"I think the 'interference' between endurance training and strength training found in some laboratory-based training studies has been overblown," said Dr. Benjamin Levine, director of the Institute for Exercise and Environmental Medicine in Dallas, which is partly run by the University of Texas Southwestern Medical Center.
"Virtually every competitive athlete knows that the best outcome comes from a combination of strength, endurance and technical training," Levine, who was not involved in the study, wrote in an email. "I am not sure why the investigators tried to combine them on the same day, but this study shows that - depending on patient preference and logistics - combining them is not detrimental."
Not surprisingly, some of the exercisers had some adverse events such as shoulder, knee, hip or back pain. One person in the aerobic group fell, receiving hand and forehead scrapes.
Levine said the study, known as LITOE, "highlights a common misperception about obese individuals - although these patients were considered 'frail,' their overall cardiorespiratory capacity was actually remarkably normal, which is common in obese individuals who have to carry around a lot of weight in their daily lives."
He added, "I look forward to seeing the follow up on these patients to learn how they do over the long term, since six months is a short time and fitness/strength/vitality is a lifelong process.”
"How easy it is going to be to replicate this in real life is still unknown," Lobelo said. "The next studies will have to tease out whether you can get people to do this in a real-life scenario."
N Engl J Med 2017.
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