Boosting Muscle Strength Improves Cognitive Function

Progressive resistance training (PRT) results in substantial improvements in cognitive function, muscle strength, and aerobic capacity in adults with mild cognitive impairment (MCI), according to a new study.

In a study of 100 adults living with MCI, researchers asked participants to undergo PRT and cognitive training 2 to 3 days per week for 6 months. Patients were divided into 4 groups and assigned a variety of activities, including a combination of resistance exercise such as weightlifting, as well as placebo resistance in the form of seated stretching, along with computerized cognitive training and its placebo equivalent.
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Overall, PRT increased upper- and whole-body strength and aerobic capacity significantly more than sham exercise, according to the authors, who also noted that higher strength scores but not greater aerobic capacity were strongly linked to improvements in cognition.

"Exercise, like medication, has specific effects related to modality and dose. The type of exercise that increases muscle strength Is resistance training (weightlifting) at high intensity," said Maria Fiatarone Singh, MD, FRACP, a professor on the faculty of Health Sciences at the University of Sydney, Australia, and a coauthor of the study.

"This means that the weight or bar feels 'hard' to lift, and you can only lift it about 8 times (one set) before you have to rest," she said. "It should be about 80% of the maximum amount you can lift or push with that muscle, and you should do 3 sets of each exercise 2-3 days per week. As you get stronger each week, you need to increase the weight so that it continually feels hard to lift."

Aerobic exercise or stretching does not have this benefit," Dr Singh said, noting that physicians can advise patients to do this at home or in a gym or class with some initial instructions. “This same exercise is safe and beneficial for heart disease, diabetes, hypertension, lung disease, arthritis, depression, osteoporosis, falls, and frailty, among other conditions," she said.

Physical exercise is "increasingly recommended as a lifestyle intervention," added study coauthor Nicola Gates, PhD, a clinical neuropsychologist at the University of New South Wales, Australia.

"There are a number of factors however that will determine the benefits from engaging in exercise," Dr Gates said. "Modality of exercise is important, as there are different forms of exercise, [such as] aerobic and anaerobic resistance training, flexibility and balance. As a rule of thumb, individuals should engage in all forms of exercise as research suggests they each have unique benefits to general health and the brain."

—Mark McGraw

Reference:
Mavros Y, Gates N, Wilson GC, et al. Mediation of cognitive function improvements by strength gains after resistance training in older adults with mild cognitive impairment: outcomes of the Study of Mental and Resistance Training [published online October 24, 2016]. J Am Geriatr Soc. doi:10.1111/jgs.14542.