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What does exercise do to your brain?

What does exercise do to your brain? Image of person using exercise bike
(Image credit: Getty Images )

There are myriad reasons for working out. You might want to get into good shape, improve your fitness, reap the mental health benefits, or simply be able to hold a conversation while you’re running. It’s well known that exercise can have great impacts on the body, but what does exercise do to your brain? 

Choosing a run over a TV marathon might help keep your physical health up, but scientists have revealed that a workout can also give your gray matter a boost. Not only does exercise help you grow new brain cells, but it can also put you in a good mood, which can have positive effects for both physical and mental health. Here’s what is happening to your brain when you work out, and how it can benefit you.

What actually happens to your brain when you work out?

Exercise can provide a way to maintain brain function, according to a study in the Trends in Neuroscience journal. The research shows that your session on the track or the treadmill increases the molecules in your brain that aid learning and protect against cognitive decline. Psychologist and mental game coach Dr. Delice Coffey adds that "Exercise helps new brain cells to grow. It aids in brain plasticity by stimulating the development of new connections between the cells and cortical areas of the brain."

The rise in these molecules, known as a brain-derived neurotrophic factor (BDNF), occurs in the hippocampus, which is the center for memory formation and learning. BDNF is a super-charged protein that helps keep brain circuitry intact. Those who have low levels of BDNF may suffer from Alzheimer’s, dementia, or depression.

According to a study in the National Academy of Sciences journal the reason why people can start to suffer from impaired memory or dementia, when they get older, is because the hippocampus will naturally start to shrink as you age. However, a study by the University of British Columbia found that heart-pumping exercise increases the size of the hippocampus; though you do need to be prepared to sweat it out as balance or resistance training exercises don’t have the same effect.

Exercise also helps keep your brain supplied with fuel. "Exercise helps get oxygen to the brain, which is essential to our survival. By increasing the heart rate through exercise, it pumps the vital oxygen the brain needs," said Dr Coffey.

When you swap the couch for a 5km run, you also make this process more efficient. "Exercise helps the heart to beat faster by pumping more blood with each beat. When your heart beats fast during exercise, it gets more blood through the body," said Dr Coffey. A healthy cardio output keeps your blood pressure at the levels needed to get oxygen-rich blood to your brain and other vital organs.

What does exercise do for your brain? Image of woman taking a rest on a walk

(Image credit: Getty Images )

Which exercise is best for the brain?

If you want to increase your gray matter, you need to be prepared to break a sweat. Dr Coffey said that exercises most beneficial to the brain are aerobic-style workouts. "Studies show that swimming and running seem to be best for brain health," said Coffey. "However, weightlifting can also increase the heart rate, which can also be beneficial to brain health." 

What does exercise do to your brain? Image of two women taking a break from a workout

(Image credit: Getty Images )

Can exercise improve your mood?

Whether you achieve the so called 'runner’s high', or not, exercise has been found to reduce symptoms of depression and anxiety. A study in the International Journal of Neuropsychopharmacology found that the antidepressant effect of running is due to more cell growth in the hippocampus.

Interestingly if you work out in a group, a study in the journal of Adaptive Human Behavior and Psychology found the brain will release natural pain relieving Endogenous Opioid System to help encourage social closeness. A good everyday example of this would be a rowing team that finds the strength to power through to the end of a race. 

Exercise doesn’t just boost your heart rate, help you sleep better and reduce stress, but it also improves your diet. A study in the International Journal of Obesity discovered in 2019 that the more vigorously a person exercises, the more they start to choose healthier foods. In a study of 2,680 sedentary adults, they found that the ones who started working out were more likely to choose nutritious foods, like lean meats, fruit and nuts, and less likely to choose fried foods, soda and snack foods.” An additional study in the journal Appetite found that intense exercise even kickstarts appetite-regulating hormones.

So whether you like the idea of going for a run or not, it’s clear that a heart-pumping workout is a smart move. If you're not sure where to start, though, we have a guide to how to get fit to start you off.

Claire Turrell

Claire Turrell is a freelance journalist based in Singapore. She was the launch editor of SHAPE Middle East. Her work has been published by Nat Geo, Harper’s BAZAAR, Insider and the BBC.