Studies show that exercise improves cognition by acting on both brain structure and function. For example, exercise builds brain tissue, according to a study at the University of Illinois. Researchers assigned groups of over-sixty adults to six months of either aerobic exercise or toning and stretching and found that aerobic exercisers had higher brain volume than the others, suggesting that exercise spares brain tissue lost during aging and enhances cognitive health.
A 2009 study in the journal The Physician and Sportsmedicine notes that exercise promotes the creation of new neurons, increases brain volume, and improves cognitive function—all of which help aging brains retain plasticity, or the ability to create new neural connections. Not only does exercise increase the number of neurons, but it also improves their responsiveness and regulates important neurotransmitters responsible for cell communication, helping you stay sharp.
Regular exercise may also delay the onset of dementia and Alzheimer’s disease, reported researchers in a 2006 study in the Annals of Internal Medicine. The study followed 1,740 people over the age of sixty-five and found that, over the course of six years, those who exercised at least three times a week were 32 percent less likely to be diagnosed with dementia during the study. The authors suggest that this reduced risk might be because frequent exercisers have less brain tissue loss in the hippocampus, one of the earliest areas of the brain to be affected by Alzheimer’s disease.
Age-related damage to blood vessels and reduced blood flow to your brain (blood flow typically declines with age) can lead to impaired mental function and even vascular dementia. So another advantage of exercise is that it boosts oxygen-rich blood flow to your brain. A small study in the American Journal of Neuroradiology revealed a possible reason for the increased circulation: Researchers found that, out of fourteen healthy adults in their sixties and seventies, those who exercised had more small blood vessels in their brains and less age-induced twisting in those vessels.
Experts aren’t sure yet how long or hard you need to exercise for the best brain results, or if one type of exercise is better for your brain than others. But most recommend that you aim for at least thirty minutes of moderate aerobic exercise on most (or all) days of the week. In fact, a 2010 study published in the Archives of Neurology found that moderate exercise in midlife or late life decreased the risk of mild cognitive impairment more than light or vigorous exercise. Exercising outdoors may boost brain health even more, suggests a 2008 study in the journal Psychological Science. Researchers found that people who walked in natural environments performed better on memory and attention tests than those exercising in urban settings.
Most research has focused on the benefits of aerobic exercise, but a 2010 study in the Archives of Internal Medicine demonstrated that strength training improves cognitive function as well. In the study, sixty-five- to seventy-five-year-old women who performed resistance training exercises (such as lunges and squats) once or twice a week had significantly better scores on tests measuring mental focus and conflict resolution than the control group, who did balance and toning exercises.
In addition to sustained exercise, daily activity may also help you keep your wits about you. In a 2008 study in the Journal of the American Geriatrics Society, researchers asked more than 2,700 women in their eighties to wear a watchlike device that measured all of their daytime movement, from walking to gardening to shopping to playing bridge. The women who were the most active showed better cognitive function and were the least likely to show signs of cognitive impairment.
In short, the same kinds of activity that benefit the rest of your body are good for your brain as well. The most important thing is that you get moving!