The Runner’s High: What Happens In The Brain And Why It Feels Good

When it comes to the legendary “runner’s high”, people often fall into one of two camps: the true believers, and the staunch deniers. While it’s true that not everyone feels fabulous after a long run, runner’s high is a real phenomenon. But what causes it? And if you’ve never felt it yet, is there still hope?

What is runner’s high?

Runner’s high is the term given to a feeling of euphoria brought on by a period of exercise. While runners speak about this particularly often, other cardio workouts can have the same effect, such as cycling or rowing.

For those who experience it, the euphoria typically starts about 30 minutes to 1 hour into a run, but this can vary depending on individual levels of fitness, according to Medical News Today. Some research has even suggested that this feeling is so rewarding, it’s why humans evolved to exercise in the first place.

However, it’s important to say that this is not at all a universal phenomenon, even among very experienced runners. “Indeed, many distance runners feel merely drained or even nauseated at the end of a long race, not blissful,” said professor of neuroscience David J. Linden, speaking to Johns Hopkins Medicine. They also poop themselves surprisingly often, which probably doesn’t help matters (if we must be burdened with this knowledge, so must you).

This sentiment was also echoed by competitive trail runner Lou Clifton in an interview with the Guardian. “I guess generally when I’m running, there’ll be a point where I settle into a bit of a groove and it’s quite comfortable,” she said, but stopped short of calling this feeling a “high”.

What causes runner’s high?

It’s possible that not every Runner™ in your life is being entirely truthful when they extol the rush of a quick 10K before work, but some people really do get “high” off exercise. So, what’s behind this effect?

Many will confidently declare at this point that it’s “something to do with endorphins” – but Linden explained that this is likely a misconception, as endorphins can’t pass the blood-brain barrier. While these so-called “happy chemicals” certainly are released in response to exercise, neuroscientists have known for a while that they’re unlikely to be the real drivers of exercise-induced euphoria.

Instead, more recent research is pointing to a different system altogether: the endocannabinoids. These are the body’s own versions of compounds like CBD and THC from the cannabis plant, which research suggests are good at chilling us out and helping us destress.

A study in 2021 demonstrated that blocking opioid receptors – the receptors that endorphins bind to – using the drug naltrexone didn’t stop people feeling a post-workout high. That indicated that something other than endorphins must have been at work, and the authors suggested that endocannabinoids could be the answer.

Further work has collected together what we know about endocannabinoid release in response to different types of exercise. A 2022 meta-analysis concluded that acute exercise consistently boosts levels of endocannabinoids, and that moderate activity is more effective than lower intensity workouts.

The consensus seems to be that endocannabinoids are a far more promising candidate than endorphins, but that lots more studies are needed to tease out exactly what’s happening there.

How do you achieve runner’s high?

If you’re looking for a more sophisticated answer than “get your trainers on and go for a run”, don’t worry, we’ve got you covered.

Speaking to Runner’s World, professor of biological sciences David Raichlen suggested that setting your workout intensity to keep you at 70-85 percent of your maximum heart rate is best if you want to boost your endocannabinoid production. You can calculate this based on your age.

From their research into why the runner’s high seems so elusive for some people, Steven Hicks, an associate professor at Penn State, added that it can be worth switching things up. Try running different distances, or intervals of sprinting, to stop things from feeling too routine.

But some people will simply never get to experience the runner’s high, and that’s okay. You’ll still be reaping all the benefits of regular exercise, even if at the time it feels like a slog.

“Voluntary exercise is the single best thing one can do to slow the cognitive decline that accompanies normal aging,” Linden said, which can only be good news. You’ll also be helping your heart and lowering your risk of various diseases.

If you’re thinking of taking up regular exercise after a long break, it’s best to start slow and consult your doctor first. But otherwise, get fuelled up, get out there, and chase that high.

The content of this article is not intended to be a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of qualified health providers with questions you may have regarding medical conditions. 

All “explainer” articles are confirmed by fact checkers to be correct at time of publishing. Text, images, and links may be edited, removed, or added to at a later date to keep information current. 

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