November 29, 2015
A few brisk walks a week may be all it takes to help keep the mind sharp with age, a new study found.
Earlier studies have found that physical activity is important for maintaining brain health. But encouragingly, these recent findings suggest that the exercise need not be particularly intense or rigorous to have benefits for the brain.
For the study, researchers at the University of Kansas recruited 101 older adults, aged 65 and over, who were free of Alzheimer’s or other serious memory problems. All were in generally good health, but they got little exercise.
They were divided into four groups. One group was instructed to walk briskly for 75 minutes a week. Another group walked for 150 minutes per week. A third group walked for a total of 225 minutes per week. And the fourth group, which served as a control, went about their usual, sedentary routine.
Those assigned to an exercise group reported to their local YMCA, where personal trainers guided them through a walking program. They started slowly and worked up to their target goals of 75 to 225 minutes a week, walking briskly for three to five days a week and never for longer than 50 minutes at a time. Some did their walking on elliptical trainers, but no more than once a week.
At the end of 26 weeks, the study participants were given comprehensive physical exams and tests of thinking and memory skills. Not surprisingly, all of those who walked improved their aerobic fitness. And the more they walked, the more physically fit they had gotten.
The exercisers also tended to score higher on several measures of cognitive health, including the ability to focus and pay attention as well as their ability to navigate visual and spatial challenges. Both mental abilities tend to decrease with age and are impaired by Alzheimer’s disease.
But encouragingly, the benefits of exercise were apparent even with just a small “dose” of exercise — a few short walks a week — the researchers found. “Our data suggest that high levels of exercise are not necessary to achieve fitness and cognitive benefits in those who adhere to the exercise program,” the authors concluded.
Earlier studies have suggested that walking can be good for the brain. People who get a lot of physical activity tend to score higher on tests of memory and thinking skills as they age. They also have a lower risk of Alzheimer’s and other forms of dementia. People who are aerobically fit also tend to have slower rates of cognitive decline as they age. Exercise has also been shown to have benefits for those with Alzheimer’s.
The authors note that their study is preliminary and that more research is needed to determine the optimal “dose” of exercise for the brain. They plan to study further how exercise may help to delay – and perhaps even prevent — the onset of Alzheimer’s disease and other forms of dementia.
Source: Eric D. Vidoni, David K. Johnson, Jill K. Morris, et al: “Dose-Response of Aerobic Exercise on Cognition: A Community-Based, Pilot Randomized Controlled Trial.” PLOS One July 9, 2015