Chasing the runner’s high: The elusive buzz scientists are still figuring it out | Health & well-being

Ia reluctant runner. Two or three times a week, I stagger through the streets and alleys of my neighborhood, motivated only by the company of my running companion and the anticipation of the food I’ll enjoy on my way home.

The idea of ​​a runner’s high hovers on the horizon, like a neurochemical mirage. Maybe once on a longer race I felt like my feet had sprouted wings and for the first time in my racing life I really wanted to keep going.

The promise of intense exercise sounds like a cruel joke made up by personal trainers, but some runners are talking about drug addiction, and scientists think there’s something to it: they just don’t know exactly. what is it about.

Neuroscientist Dr Hilary Marusak from Wayne State University in Detroit, USA is a runner who has taken top-speed running to the next level. His research explores how exercise interacts with brain chemistry, with a view to using this knowledge to help understand and treat mental health disorders.

Figuring out exactly what “runner’s high” is is tricky. Not everyone who runs seems to experience it, but those who do report a feeling of well-being, almost euphoria, that kicks in at some point during their exercise – it can be after a few minutes , it may be after 20 minutes. And it doesn’t just have to be running: it can happen with other intense exercise like biking, swimming, or even rock climbing, but it doesn’t seem to happen with team sports. What’s not yet understood is how long it lasts, why some people get it but not others, what triggers it, and what happens in the body when it happens.

Marusak says the runner’s high has long been believed to be an effect of endorphins, which are opioid-like hormones the body releases in response to stress or pain to relieve that pain. But “the last two decades have really disproved that idea with some interesting scientific research,” Marusak says.

For example, if a drug like naltrexone is used to block the effects of these local endorphins, people still get the runner’s high, she says. Endorphins are also enough large molecules, and they cannot cross the blood-brain barrier – the special lining of blood vessels in the brain that protects the brain from chemical or biological damage – so their effects are felt much more regionally: the nerve endings in the muscles, for example. Both of these suggest that endorphins may play a limited role in runner’s high.

Another system that could be involved is the endocannabinoid system which, as the name suggests, is the one that cannabis interacts with. Endocannabinoids are small enough to cross the blood-brain barrier, where they interact with receptors that control a range of functions, including mood and inflammation.

Doctor Francis Chaouloff, a neuroscientist at Neurocentre Magendie – a research institute in Bordeaux, France – explored the role of endocannabinoids in exercise, studying a key endocannabinoid receptor called CB1 in mice. “If you remove the CB1 receptor or if you block the CB1 receptor, you will see that the mouse will run less,” says Chaouloff. He thinks this could be related to the fact that CB1 receptors are found in particular in a part of the brain associated with reward.

But it says more about the fact that the mice are motivated enough to point their nose at a target which then allows them to jump on the steering wheel to jog. This motivation can be quantified in mice, but it’s much harder to study how they feel while doing it, and whether they get the “high.” “They never fill out questionnaires,” jokes Chaouloff. What his research suggests is that endocannabinoids are important in motivating us to run, and may also be why regular runners really miss it when they stop running; there is a sort of withdrawal effect when these endocannabinoids are not released.

Lou Clifton is an internationally competitive trail runner whose successes include being the first in her age group and the first Australian to cross the line in the grueling 160km Ultra-Trail ultra-marathon du Mont-Blanc in France last year. She runs for many reasons – the sense of accomplishment, being with friends, being in nature, testing her limits – but she’s not sure if there’s a specific ‘high’ she notices when she runs. .

“I guess usually when I’m running there’s a point where I sort of settle into a rhythm and it’s pretty comfortable,” she says. “When I finish a race, I definitely got that high, because I think then you have all that joy of finishing and the adrenaline.” She also had the difficult times of not running, when illness or injury prevented her from going out for even an easy 10km trot.

One thing that seems to be clear is that exercise intensity is important in triggering the runner’s high, Marusak says.

“It appears that moderate activity — above 50% of maximum heart rate — is more effective at getting a cannabinoid boost than lighter exercise, like brisk walking,” she says. “We know they’re synthesized on demand in response to a stressor and exercise is definitely a stressor.” But it’s unclear whether the more intense the exercise, the more intense the high.

As a runner herself, Marusak also wants to know how to get the most out of that post-run high, and therefore how long it will last. “If I have an exam or something I need to do at work, I want to time my exercise so I can continue to get those brain benefits, but does it have to be within an hour or can it be a few hours? later ?”

There are many more questions than answers about this tantalizing but elusive phenomenon. But with even seasoned runners admitting that at least the first few minutes of a race can be tough and unpleasant, we may not need to look this gift horse in the mouth. Anything that gets us off the couch and into physical activity is a good thing.