Running makes brain bigger. It’s true, says Grit Doctor

Neuroscientists found that thousands of new brain cells grew in mice when they ran

Gráinne Loughran wrote an interesting piece in The Irish Times a few weeks ago (October 24th, 2016) about balancing parenthood and academia. She raised questions about the incompatibility of the two. As a part-time student and parent, I found myself nodding sagely to all the challenges, but then immediately had the thought of the almost perfect compatibility of academic studies and running.

My children are now at school, so I can’t begin to imagine what it is like to study full-time when you are at the very beginning of this parenting journey. I applaud anyone who tries. For me, juggling work commitments with a part-time master’s degree and six-year-old twins has still been a massive challenge. I knew right from the start that I wouldn’t allow my study commitments to interfere with regular running, because I’d need those runs to keep on top of things. What I hadn’t anticipated was how much running seemed to literally help me with my studies. I found that after I ran it was easier to write.

It is often said that the brain is like a muscle. And on these regular sanity-saving runs – not to be underestimated for any deranged juggling mum – I was certainly giving mine a good workout.

I was always thinking hard about whatever assignment I was working on, and I began to notice that many of my best ideas occurred to me during the run – lines of poetry for example (yes, our first assignment was to write poetry), or arguments for critical essay writing. So much so, that I started bringing a tiny notebook and pencil with me on my runs.


Joyce Carole Oates, American author and professor of creative writing at Princeton University, puts it beautifully: "Running! If there's any activity happier, more exhilarating, more nourishing to the imagination, I can't think of what it might be. In running, the mind flees with the body, the mysterious efflorescence of language seems to pulse in the brain, in rhythm with our feet and the swinging of our arms."

The positive effects of running on our mental health have been known for some time. For example, it alleviates the symptoms of depression through stimulating serotonin, releasing endorphins and, on really long runs, oxytocin – a potent cocktail of happy hormones that can lift our mood. More recently, however, there is a growing body of evidence that shows running literally increases our grey matter.

Experiments on running mice by Cambridge neuroscientists revealed thousands of new brain cells grew in the dentate gyrus part of the hippocampus, one of the few regions of the adult brain that can grow fresh brain cells. This increase in brain cells dramatically improved the ability of the mice to recall memories, without confusing them – a crucial skill for learning and cognition. Science cannot yet tell us exactly why, but the growth of new brain cells is quite possibly stimulated by the increased blood flow to the brain brought about by running.

Writers and thinkers have long taken advantage of this. Thoreau and Nietzsche have claimed that walking gives wings to the imagination. Virginia Woolf famously went on long treks throughout London for her writing inspiration. More recently, Haruki Murakami looked at his relationship with running and writing and the mysterious and incredible ways they intersect in What I Talk About When I Talk About Running. Some of that mystery it seems has been solved by this research – in finding a mechanism for it.

Running also reduces stress. And stress stimulates the hormone cortisol which inhibits the growth of new brain cells. Stress undeniably poisons creativity so anything that can help reduce it is bound to be good news for my studies. There is a sweet spot though, which you will need to discover for yourself because vigorous exercise (especially if you are very unfit and overdo it) can cause stress, stimulate cortisol and give you the opposite poisonous effects. My sweet spot is a slow four-miler.

Sometimes when I get back to my desk afterwards it occurs to me that the solution I’ve found, or the idea I’ve had is glaringly obvious. But perhaps they became obvious only because I was relaxed enough to find them. Or relaxed enough to remember them. I’m also convinced – and this is common sense really – that being free of any other distractions when running gives my brain space to breathe and flex its muscle.

Give it some fresh air, a pounding heart, a screen-free 30 minutes or so, and a rush of blood and you just might find the answer to whatever knotty question you’re grappling with. It’s a lovely idea anyway, and I for one am going to run with it.

The Grit Doctor says: Running makes you brainier. Factoid.

Ruth Field is author of Run Fat B!tch Run, Get Your Sh!t Together and Cut the Crap.