Finally, a prescription for the precise amount of exercise you need to keep your brain in tip-top shape: After reviewing 98 clinical trials, researchers determined that working out for at least 52 hours over the course of six months can help older adults stay mentally sharp.
Exercise had the greatest impact on “processing speed and executive function,” study author Joyce Gomes-Osman, Ph.D., of the University of Miami Miller School of Medicine, told MedPage Today. (Executive function is the ability to plan, organize and complete tasks.) “This is evidence that you can actually turn back the clock of aging in your brain by adopting a regular exercise regimen,” she went on to say.
The findings are based on a review of close to 100 clinical trials, which led to a total of more than 11,000 participants with an average age of 73. The past trials tested the cognitive benefits of various exercises, including walking, biking, dancing, strength training, tai chi, and yoga, practiced for a range of four weeks to a year.
After analyzing the data, Dr. Gomes-Osman and colleagues at the Berenson-Allen Center for Noninvasive Brain Stimulation at Beth Israel Deaconess Medical Center (BIDMC) found that aerobic workouts (like running or Spinning) along with strength-training and mind-body activities (like yoga) all boost brain power.
“It’s very encouraging that the evidence supports all sorts of different exercise interventions, not just aerobic, to improve thinking abilities,” said Alvaro Pascual-Leone, M.D., chief of the Division of Cognitive Neurology and the director of the BIDMC, in a release. Dr. Pascual-Leone added that the effect could be seen in both healthy older adults and those with “mild cognitive impairment.”
Of the aerobic interventions included in the review, the most common one was walking, which Dr. Gomes-Osman said is reassuring. “You don’t need to be running,” she told MedPage Today. “If you start walking, you’re going to get benefit. But this is not window-shopping; this is walking. It’s physical exercise, not just physical activity.”
As for the very recommended dose of 52 hours over the course of six months, Dr. Gomes-Osman clarified in Time that it’s not “a magic number.” And although the average amount of time people exercised was about one hour three times a week, you don’t necessarily need to adhere to that regimen.
“There really is a range,” said Dr. Gomes-Osman. The more important thing to keep in mind is the six-month — or longer — commitment. “These results signify to us that in order to get the known benefits of exercise for the brain, to help areas involved in thinking and problem solving — to get that machinery going — you need longer exposure.”
Dr. Gomes-Osman’s goal is to be able to provide practical advice about exercise and brain health to individuals. “I believe in giving people knowledge about outcomes,” she said in MedPage Today. “If you tell people to be active, they may be less interested overall than if you say, ‘You can do this, this, this or this, and you need to keep it up a couple times a week for about six months, and then you should get a benefit.’ I think that’s a better sell for patients.”