Does physical fitness lead to cognitive fitness?

Created date

August 22nd, 2019
A group of older people in exercise clothes stretch while sitting on the grass in a park.

According to the Alzheimer’s Association and the National Institute on Aging, 5.7 million people in the U.S. have dementia, with Alzheimer’s disease accounting for most cases, followed by vascular-related causes. 

Despite this high prevalence, which is projected to almost triple by 2050, medical science still hasn’t found a foolproof way to prevent or slow the progression of symptoms that rob people of their health and independence.

One action stands out, however, as very promising: regular physical activity.

Compelling research

Numerous studies and systematic reviews have shown that people who exercise regularly have a reduced risk of developing dementia-related disease. Even when controlling for other factors, a strong association remains between physical activity and brain health.

Perhaps more compelling is evidence that exercise may slow down the progression of cognitive problems once they have started—a condition known as mild cognitive impairment (MCI). Losing things, forgetting appointments, or having problems coming up with a friend’s name are symptoms associated with MCI. According to the National Institute on Aging, people with MCI can still carry out most daily activities and do not demonstrate personality changes or other symptoms indicative of advanced dementia.

In a study of people with MCI, a 12-week exercise program improved memory and brain function. Another study from researchers at the University of California showed that a single six-minute period of moderately vigorous activity improved memory function in people with preexisting memory problems.

Exercise can improve more than just memory. “Research shows that a set of more complex mental processes called executive function seems to improve the most from exercise,” says Matt Narrett, M.D., chief medical officer for Erickson Living. “Executive function is the ability to apply past experience to your current actions. Activities that require executive function include balancing a checkbook, organizing a project, and managing your time.”

Why exercise may be effective

As of yet, no definitive cause and effect has been found between physical activity and brain function, but there could be several reasons why exercise has a positive effect.

“Among other bodily benefits, it keeps blood vessels that feed your brain healthier, and thus more oxygen can be delivered to vital tissue,” says S. Marc Testa, Ph.D., clinical training director, division of neuropsychology at the Sandra and Malcolm Berman Brain and Spine Institute at LifeBridge Health in Baltimore, Md.

“Exercise may also strengthen connections among nerve cells, reduce inflammation, or stimulate hormonal changes that have a positive effect on the brain’s structure and function,” Narrett adds. 

Being active also lowers your risk of developing chronic conditions that put you at a high risk for dementia in the first place, such as heart disease, peripheral vascular disease, high blood pressure, and diabetes.

How much is enough?

For older adults, the Centers for Disease Control and Prevention (CDC) recommends several ways to get the proper amount of exercise. You can do 2 hours and 30 minutes of moderate-intensity aerobic activity each week, or 1 hour and 15 minutes of vigorous-intensity aerobic activity (such as jogging) every week. The third option is engaging in an equal mix of moderate- and vigorous-intensity aerobic activity. You can break any of this time up into ten-minute blocks, if you prefer. To round it out, experts also say older adults should add muscle strengthening, flexibility, and balance exercises a few times weekly.

Adhering to the CDC guidelines can be difficult, but if you can’t, there is good news—an increasing number of studies are concluding that any amount of activity can help, and the CDC recommends that seniors should be as active as they are able. “Even simple exercises and stretching can be beneficial,” Narrett says. 

Exercise shouldn’t be something you dread—give yourself credit for daily activities such as cleaning, gardening, or following the grandkids around. “Other ways to be active include chair activities, doing some stretching when you wake up, taking stairs instead of an elevator, or parking farther away than usual from a store entrance,” Narrett advises.

Before starting any new exercise or physical activity to your daily schedule, check with your doctor, who can help you develop an individualized plan.


When a little is a lot

In a study of older adults, including 90 pairs of twins, light exercise such as gardening or walking was associated with reduced likelihood of dementia. 

Source: The Journals of Gerontology, Series A: Biological Sciences and Medical Sciences