Can Exercise Change Your Brain?

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What if you could take a pill that would do all of the following: both treat and prevent obesity, prevent cardiovascular disease, improve mobility, improve mood, provide stress relief, improve overall quality of life, prevent diabetes, improve healthy longevity, prevent dementia, and even prevent sudden cardiac death?

We now know that exercise can do all of the above. And, as an added bonus, scientists have now discovered that regular exercise can actually keep your brain young.

Exercise Literally Changes the Brain

Scientists who study the brain and nervous system (known as neuroscientists) have discovered that aerobic fitness can change which areas of the brain activate in order to process mental tasks.

Adults younger than 40 need to use only a small part of their brains to perform cognitive tasks; as we age beyond 40, however, most of us require more of our brains to perform the very same tasks. Researchers performed brain imaging studies on 60 Japanese men between the ages of 64 and 75, and found something remarkable: the men who were most physically fit needed to use only the small part of their brains to perform cognitive tasks—as though their brains were the same as those less than 40 years of age!

This indicates that regular exercise to maintain aerobic fitness can actually keep you mentally young.

How Much Exercise Do You Need?

Thankfully, you don’t have to be able to run a marathon in order to reap these benefits.

Research has shown that regular exercise of moderate intensity (such as brisk walking), for at least 30 minutes per day, is all that is needed to maintain an aerobic fitness level that will keep your brain young and prevent cardiovascular disease.

Most national and international guidelines recommend getting at least 150 minutes of moderate-intensity exercise every week.

This can translate into 30 minutes of moderate-intensity exercise five times per week, for instance. And research has borne out the health benefits of a daily 30-minute walk: in the Nurses’ Health Study, for instance, those who walked briskly or otherwise achieved moderate-intensity exercise for at least 30 minutes every day had a low risk of sudden cardiac death during 26 years of follow up.

Additionally, according to the Physical Activity Guidelines for Americans from the U.S. Department of Health and Human Services (HHS), obtaining at least 1 hour and 15 minutes of vigorous-intensity exercise weekly can meet the minimum amount of recommended exercise.

Vigorous-intensity exercise includes physical activities such as hiking uphill, bicycling at or above ten miles per hour, fast swimming, running, traditional aerobics, and heavy shoveling or ditch digging, among others.

The HHS guidelines note that additional health benefits can be obtained by increasing the amount of moderate-intensity physical activity to at least five hours per week, or increasing vigorous-intensity exercise to at least 2 1/2 hours per week.


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Hyodo K, Dan I, Kyutoku Y, et al. The association between aerobic fitness and cognitive function in older men mediated by frontal lateralization. NeuroImage 2016;125:291-300.

Physical Activity Guidelines for Americans. United States Department of Health and Human Services. Accessed online at on June 12, 2014.

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