We have heard time and again the importance of living an active lifestyle. But exactly how much exercise we need to gain various health benefits, including heart health and brain health is still unclear. A recent study aimed to determine just how much exercise is needed to improve your ability to think.
Researchers recruited 101 sedentary older adults, at least 65 years of age, who were generally healthy, with no symptoms of dementia or other cognitive impairments. They asked them to complete a series of tests, including measurements of their aerobic capacity and how well they could remember and think. Volunteers were then randomly assigned to one of four groups including a control group.
People in the other three groups were assigned to walk briskly. One group began exercising for 75 minutes per week, which is half of the current recommendation of 150 minutes per week of moderate exercise. Another group was assigned to exercise for the recommended 150 minutes per week. And the third group was told to exercise for 225 minutes per week, or 150 percent of the recommended amount. Volunteers reported to a local YMCA for supervised workouts on a treadmill for anywhere from 25 minutes to an hour. After 26 weeks, all of the participants returned to the lab to repeat the original tests.
Physical results were as expected. The more someone had exercised, the more his or her endurance capacity had increased. The volunteers in the control group were no more fit than they had been; those in the group exercising for 75 minutes per week were somewhat more fit; those exercising for 150 minutes per week were fitter still; and those walking for 225 minutes per week were the most fit of all.
As for cognitive improvements, in general, the researchers found that most of the exercisers showed improvements in their thinking skills, especially in their ability to control their attention and to create visual maps of spaces in their heads, two aspects of cognition that are known to decline with age. However, these gains were roughly the same whether people had exercised for 75 minutes a week or 225 minutes. Those volunteers who had exercised the most scored slightly better on some cognitive tests at the end of the study period than those exercising less, but the difference was not considered significant.
Researchers concluded that over all just a small amount of exercise may be sufficient enough to improve many aspects of thinking and more exercise may not provide noticeably more cognitive benefit. This certainly does not negate the positive physical benefits of more exercise versus less.
The important finding from this study is that briskly walking for 20 or 25 minutes several times a week (an amount of exercise achievable by almost all of us) may help to keep our brains sharp as we age.