How Exercise Keeps Your Brain Young

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“Your brain will eventually enjoy exercise for exercise’ sake, right; endorphins and endocannabinoids will create a sense of reward , but it doesn’t know that at first.”

Charles Duhigg

Want a younger brain? How about better memory? Then this blog post is for you. Read on and I’ll explain.

We all know exercise is good. And when asked why we do it, most of us would say we want a six-pack or get rid of unsightly bingo wings. But few would say they want to grow more brain cells. But that’s exactly what happens.

Not too long ago scientists thought the human brain starts going downhill from around age twenty-five — twenty-five! Fortunately, we now know that neurogenesis — the creation of brain cells — can happen well into old age, even nineties and beyond.

Why would movement affect the brain?

Think back to the first humans. Their environment was new. Everything was new. They had to get out there to explore and learn new things; what was food and what was predator; what was edible and what wasn’t; who was friend and who was foe.

Put simply, movement prepared the brain for new experiences, and the ability to learn from them, by making new neurons and increasing the volume of the brain.

Also, with no Lidls or Walmarts around the corner, early humans had to track down, hunt and kill their dinner — not something you’d do sitting down.

So how does it work?

Movement, be it walking in the park or up the stairs, cycling, or jogging puts your muscle cells to work. The largest muscles are those in your butt and thighs, and just taking the stairs instead of the lift (or, elevator for non-UK readers) can break down up to sixty percent of the glucose floating around in your blood.

And once you put your muscles to work, they begin producing proteins called myokines which are then released into the blood stream. Myokines have a range of effects: some make you feel alert, some act as antidepressants and others work like pain killers.


The hippocampus is your brain’s memory centre — think of it as HQ. From about age thirty-five, the volume of the brain shrinks by roughly half a percent every year, and the hippocampus shrinks too. And that’s why memory worsens with age. But it’s not all gloom and doom because exercise increases the volume and creates new nerve cells — at any age.

How much exercise does the brain need to grow younger?

A year-long study split 120 people into two categories: one did gentle stretching exercises, the other walked briskly for 40 minutes three times a week. By briskly I mean fast enough to up the pulse rate a few notches. Or, walking fast enough to become slightly out of breath.

A year later, the brains of the stretch group had, as predicted, shrunk in volume by 1.4 percent. And the group that had done more pulse-raising exercise? Drum roll, please. The volume of their brains… wait for it… had increased by two percent! In other words, their brains had grown two years younger!

And there’s more…

The hippocampus is not the only part of your gray matter that’s impacted by exercise; the frontal lobe is too. This is where the decision maker of your brain — the boss — lives. When faced with contrasting messages, like in the colour test below, it’s the frontal lobe that works out what to do.

A simple example of the frontal lobe in action coupled with the effects of exercise was done on a group of older adults, all regular exercisers. Cards, each with a colour written on it, but in different-coloured pens, were shown to the participants, one by one.

So, the word ‘red’ was written with a green-coloured pen, the word ‘blue’ was written with a red-coloured pen; you get the idea. Each person then had to say the colour the word was written in, not the word itself, as fast as they could.

And, yes, it might sound simple, but it’s something the brain gets worse at with age — unless one keeps active. But in this test, all the older adults — some of them ninety-plus — aced it, outperforming 30-year-old couch potatoes. Now, if that’s not an incentive to get moving, I don’t know what is.

In the ‘colour card test’ active ninety-year-olds performed better than sedentary thirty-year-olds.

Learning about this while writing this post made me realise that exercise is not primarily what we’ve been led to believe — something you do to keep your body fit and healthy.

Rather, from an evolutionary point of view, exercise primes your mind; it prepares you for new learning, new experiences. The fit and healthy body is secondary — a happy by-product.

This is such a huge topic that I’ve just touched on. Hopefully you found it interesting. Please like, share or comment — I’d love to hear your thoughts.

Until next time,