The Runner’s High: Running Folklore or a Science-Based Feeling?

There are over 600 million estimated runners worldwide. Ask those runners if they’ve ever experienced a runner’s high, and you’re sure to receive a mixed bag of answers. Most, however, would say they have never experienced it. Every runner chases it, but only some runners can report having experienced it.

So, if that’s the case, is the runner’s high real? Or is it just a bit of running folklore?

What is the runner’s high?

The runner’s high is the feeling of weightlessness a runner feels during a run. Your every step feels easy, your muscles aren’t aching or in pain, and you feel euphoric as you run. It’s as if nothing can bring you down.

The feeling is elusive, however, and not every run is going to deliver a runner’s high. In fact, most runs aren’t going to provide this feeling. But when it strikes, it’s rewarding, and that’s what makes running so addictive for those who’ve achieved it.

It’s a similar feeling to being in a ‘flow’ state. Or, as Mihaly Csikszentmihalyi explained, “a state in which people are so involved in an activity that nothing else seems to matter; the experience is so enjoyable that people will continue to do it even at great cost, for the sheer sake of doing it.”

Most of us know this feeling or have at least heard about it. You’re writing a paper or working on something that requires intense focus. The world seems to fade away, and time becomes distorted. Nothing else matters except for this singular activity you have been working on for some time.

But what is causing these feelings? How do we enter into this state?

Let’s look at a bit of history into the research of the runner’s high first.

The runner's high feels like running on cloud nine.
Photo by Maridav

Early on, we thought it was only endorphins

The ‘runner’s high’ craze began in the 1970s, right when running had its first boom, and everyone and their mother seemed to be heading out for a jog.

Initial research pointed to the release of endorphins that caused a runner’s high, which has become popularized, and you’ll frequently hear many fitness enthusiasts talking about endorphins after their workouts.

If you’re unfamiliar with endorphins, they are the chemicals our body naturally produces to help us manage pain or stress. They also go by the nickname, the “feel-good chemical”.

Endorphin-release results in increased happiness, a feeling of euphoria, and pain relief across your body. Opioids used for medical procedures work similarly to endorphins and help with pain relief after surgery or other procedures.

In the 1980s, scientists studied opioids in more detail. They discovered we have special receptors in our brain specifically for these types of chemicals. The receptors bind with endorphins to create the ‘high’ humans feel with the release of the chemical.

Regular exercise is associated with the release of endorphins. This is why medical professionals recommend exercise for combatting anxiety, depression, and similar ailments.

Yet, further research has found it’s not just endorphins that aid in producing a runner’s high.

But wait, what about endocannabinoids?

Researchers didn’t stop at endorphins, though, and continued their research into what caused the ‘high’ feeling during/after a run. As researchers looked closer, they observed that endorphins don’t pass through the blood-brain barrier. Therefore, these chemicals couldn’t be the only explanation for a runner’s high.

However, endocannabinoids—specifically one called anandamide—can.

Endocannabinoids, you may have guessed, are the chemical that activates the high people feel when smoking marijuana.

A team of German researchers in 2015 performed a study on mice and the release of endocannabinoids after exercise. They researched its correlation with the reduction of anxiety and pain.

To explore this, the researchers split a group of mice into two groups. One group would receive regular exercise on a wheel, while the other group remained sedentary. The regular exercise consisted of five hours of running on a wheel.

Post-run, the mice showed a dramatic decrease in anxious behaviors—demonstrated by how often the mice darted from well-lit areas to dark areas to hide—compared to the sedentary group.

In addition, the exercise group showed higher levels of pain tolerance, tested by their tendency to jump or lick their paws while being on a hot plate.

Lastly, to further explore their findings, researchers gave the mice endocannabinoid and endorphin antagonists. Essentially, these are molecules that block the receptors in the brain for these chemicals.

Upon doing this, the “endorphin antagonists did not significantly affect results, but mice treated with endocannabinoid antagonists and mice genetically engineered to lack endocannabinoid receptors were still anxious and sensitive to pain despite having run for hours.”

These findings suggest endocannabinoids are critical in helping runners achieve the famed runner’s high.

Endorphins and endocannabinoids are the most famous chemicals believed to contribute to this effect. However, researchers believe there could be more chemical compounds contributing to it.

What purpose does a runner’s high serve?

The runner’s high is theorized to serve an evolutionary purpose aimed at encouraging regular aerobic exercise. It may have been a critical reason humans were able to survive and adapt.

Researchers at the University of Arizona performed a study on the difference in the neurobiological rewards between cursorial mammals (animals adapted to run) and non-cursorial mammals (animals not adapted to run).

The researchers recruited a group of humans and dogs (cursorial mammals) and a group of ferrets (non-cursorial mammals) to run and walk on a treadmill. The researchers collected blood samples before and after 30 minutes of exercise.

Following the exercise, the humans and dogs showed a significant increase in the release of exercise-induced endocannabinoids. The ferrets, however, did not show an increase.

This led researchers to suggest “a neurobiological reward for endurance exercise may explain why humans and other cursorial mammals habitually engage in aerobic exercise despite the higher associated energy costs and injury risks.”

The chemicals associated with the runner's high may have been a key factor in our evolutionary success.
Photo by Gorodenkoff

In laymen’s terms, we run because it feels good.

This feeling could explain how humans developed as hunter-gatherers and the endurance running necessary to catch different prey. These animals could run faster than early humans but couldn’t outlast them.

As well, this includes if humans were the prey. It would be necessary to escape quickly and to continue running for long periods. The need for chemicals that would numb the pain in our muscles was essential for survival.

Thus, humans who could release these chemicals efficiently would survive and pass on their genes.

What can I do to experience it more?

The science is relatively inconclusive on this, as is the science on flow state, period. It’s not something we can turn on and off. In addition, each person will have individual requirements to reach it.

There is a project seeking to know more about the flow state, and that’s the Flow Genome Project. As far as I’m aware, this is the only research being done into the flow state. If interested, I recommend checking out the research they have compiled on the subject. They offer a test where they can match you to your ‘flow profile’ which will give you insights into how to achieve your state of flow.

Trail runners, I think, are aided in this. The feeling of being in nature has its own proven benefits, and the ability to run up and through mountains, forests, deserts, and other landscapes, rewards us with the serenity and sheer natural beauty of the natural world. The conditions are perfect to enter a flow state.

Most importantly, though, there is a simple requirement to achieve a runner’s high: run! Once your body understands running is a regular part of your routine, it will be easier to have the right conditions for a runner’s high. After all, consistency is key in everything.

Also, you can try adding more challenging workouts to your running. The release of endocannabinoids and endorphins is associated with stresses you place on your body. So, by pushing yourself a bit harder in some of your workouts, you’re setting your body up for a potential release of these chemicals.

Overall, though, just run more! The associations between running and feeling better—mentally and physically—are clear. Even if you don’t achieve a runner’s high, you’re still giving your body that dose of exercise it needs to run properly. Reward your body, and it will reward you in return.


Let me know in the comments what you think. Do you think the runner’s high is real, and have you experienced it yourself? Or is it simply made up and a bunch of malarkey? I’d love to hear your thoughts and any research you have done into the runner’s high, flow state, and more.

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