There are many reasons to believe that physical activity and exercise can benefit the brain. Studies performed in both humans and animals have shown that movement of the body increases brain blood flow, and it has also been associated with factors that support brain growth and development (called trophic factors). And exercise can help with weight control, which is important, since some studies suggest that being overweight increases the risk of developing dementia. While exercise has many benefits to the brain, heart, and other organ systems, the evidence that it can prevent Alzheimer’s disease is limited. A growing body of research is helping doctors clarify the role of physical activity in the prevention of cognitive decline.
The U.S. Department of Health & Human Services, which issues the Physical Activity Guidelines for Americans, recommends at least 150 minutes (2 hours and 30 minutes) of moderate-intensity physical activity per week for substantial health benefits. Another option is 75 minutes of physical activity per week, but at a vigorous level. However, it is important to check with your doctor before beginning a new exercise program.
Do aerobic exercise in bouts of at least 10 minutes, and spread them throughout the week. If a chronic health problem won’t allow you to do the recommended 150 minutes of exercise, be as physically active as you are able.
If you’re at risk of falling, also look for exercises that will help you maintain or improve balance. Doing tai chi—which involves performing a series of gentle, slow movements accompanied by deep breathing—may help. In a small study involving a total of 66 participants, individuals who practiced tai chi over 15 weeks (three times per week, 50 minutes at a time) were less likely to experience falls—and were more likely to have improvements in cognition—than those in the control group, who were not assigned to perform this activity. Beginners can learn more through classes (online and in person), videos, books, and DVDs.