Go on, give that grey matter a good jog

Recent studies show why going for a run can help one regain a sense of control. An experiment from West Michigan University shows that running quickly for half an hour improves "cortical flicker frequency" threshold. This is linked to the ability to
Recent studies show why going for a run can help one regain a sense of control. An experiment from West Michigan University shows that running quickly for half an hour improves "cortical flicker frequency" threshold. This is linked to the ability to better process information.PHOTO: REUTERS

Studies show running can return one's focus, vanquish stress and help improve mood

It may seem obvious - as you push on through a long run, veering between sensations of agony and elation - that running can have a huge effect on your state of mind.

It is an intuitive idea that a growing number of neuroscientists have begun to take seriously, and in recent years they have started to show us what actually plays out on the hills and valleys of your grey matter as you run.

Their findings confirm that we can use running as a tool to improve the way we think and feel. And we are now learning precisely why running can return focus, vanquish stress and improve mood. But it would be crazy to believe running is a universal solution to all of our psychological challenges. Indeed, from your brain's perspective, you may not want to push it too hard.

German neuroscientists scanned the brains of some competitors before, during and after the TransEurope Foot Race, a course of about 4,800km run over 64 consecutive days.

In the middle of this extreme ultramarathon, the runners' grey matter had shrunk in volume by 6 per cent: the "normal" shrinkage linked to old age is just 0.2 per cent each year.

Luckily, the story doesn't end too badly: eight months later the runners' brains were back to normal.

Running can do more for your mood than smooth out stress. Some lucky souls gloat about their experiences of the "runner's high", which, they claim, is a powerful feeling of ecstasy and invincibility.

But if covering immense distances can be counter-productive, it is clear now that more moderate runs can result in very real benefits.

Recent studies show why going for a run can help one regain a sense of control.

An experiment from West Michigan University shows that running quickly for half an hour improves "cortical flicker frequency" threshold. This is associated with the ability to better process information.

Two others, from the Lithuanian Sports University and Nottingham Trent University, show that interval running improves aspects of "executive function". This includes the ability to marshal attention, tune out distractions, switch between tasks and solve problems.

Among the young people studied, measurable gains were clear immediately after 10 minutes of interval sprints. They also accumulated after seven weeks of training.

A study led by University of Arizona's Professor David Raichlen ties in with these results: there were clear differences in brain activity in serious runners, compared with well-matched non-runners.

For obvious reasons, you cannot run inside a brain scanner, so the neuroscientists studied the brain at rest. First, they saw increased coordinated activity in regions, mainly at the front of the brain, known to be involved in executive functions and working memory.

Second, they saw relative damping down of activity in the "default mode network", a series of linked brain regions that spring into action whenever we are idle or distracted.

Prof Raichlen's was a preliminary study, but if corroborated in the future, it will lend fresh weight to the idea that running can be a form of moving mindfulness meditation.

Brain scans show that meditation and running can have a somewhat similar effect on the brain; simultaneously engaging executive functions and turning down the chatter of the default mode network.

Again, this seems intuitively right: in the midst of a run, you are likely tuned into your bodily state, and conscious of your breath. These are all key aims of mindfulness-based practices.

Lacing up your trainers and going for a run could, therefore, be a way to reap some of the psychological benefits of mindfulness.

All of this might start to explain why some people find that running, like mindfulness, can be a useful way to overcome stress and depression.

Recent research from the Karolinska Institute in Sweden shows, at a chemical level, how running can defuse at least one important biological stress pathway.

When you are under stress, metabolic processes in your liver convert the amino acid tryptophan into a molecule with the mumble-inducing name of kynurenine.

Some of that kynurenine finds its way into your brain, where its accumulation has been associated with stress-induced depression, anxiety disorders and schizophrenia.

When you exercise, the levels of an enzyme called kynurenine aminotransferase build up in your muscles. This enzyme breaks down kynurenine into the related molecule kynurenine acid, which, importantly, cannot enter the brain.

In this way, exercising your skeletal muscles by running clears from your bloodstream a substance that can cause mental health problems.

At first glance, it is not obvious why working your leg muscles should have a direct effect on your mental state. This work is a powerful reminder that your brain is just another bodily organ.

What you choose to do with your body will, inevitably, have psychological consequences.

Running can do more for your mood than smooth out stress. Some lucky souls gloat about their experiences of the "runner's high", which, they claim, is a powerful feeling of ecstasy and invincibility.

The popular idea of the "endorphin rush" was born in the 1980s and 1990s, when studies showed the levels of beta-endorphin increase in your bloodstream during the course of a run. Beta-endorphin targets the same receptors as opiates, and has similar biological effects.

In 2008, German neuroscientists used functional brain imaging to show that, in trained runners, beta-endorphin levels spike in the brain after a two-hour run. Increased levels of endorphin activity in the brain also correlated with the runners' self-reported feelings of euphoria.

While the physical benefits of running and aerobic exercise are well established, we are starting to see why running can have profound benefits for mental health, too.

Hopefully, knowing this will redouble your will to get out there and run more often.

THE GUARDIAN

A version of this article appeared in the print edition of The Straits Times on July 03, 2018, with the headline 'Go on, give that grey matter a good jog'. Print Edition | Subscribe