The Two Sides Of “Runner’s High”

“Runner’s high” is the experience of euphoria that can come about from sustained exercise such as running. Popular wisdom holds that this is a matter of endorphins, which are indeed typically released when we exercise.

However, while that can certainly explain increased pain tolerance (due to endorphins’ activity on opioid receptors), blocking opioid receptors has revealed that this isn’t the primary mechanism of action for creating euphoria, which is unaffected by that.

So where is the euphoria coming from?

One high, multiple pathways

Firstly, regular 10almonds readers might remember How Nature Provides Us With A Surprisingly Powerful Painkiller.

That’s about how being out in nature (or even just viewing nature scenes) changes how we process pain, on a neural level. Not anything to do with expectations or emotions, but rather, physically, what the neurons of the brain do with the signals that are sent there.

The way endorphins work is a little different, and has more to do with blocking the transmission of pain signals. But, as we mentioned up top, blocking the opioid receptors doesn’t change the mood benefits of running.

Here’s the science for that, by the way: Exercise-induced euphoria and anxiolysis do not depend on endogenous opioids in humans

Readers who clicked through to read that (good for you, don’t just take our word for things!) will have noticed that an alternative is proposed as the primary mechanism of action, namely endocannabinoids.

Produced right there within each synaptic cleft (that is, the truly tiny gap between two connecting neurons), by specialist enzymes, endocannabinoids not only have analgesic properties, but also reduce anxiety—thus, directly improving mood.

Some of the same scientists from that other study, now with a lot more added to the team, went ahead and examined the effects of endocannabinoids, and in particular, anandamide (AEA), which binds to the same receptors as THC.

Firstly, you might be wondering why anandamide gets abbreviated to “AEA” when there’s only one “e” in the word and it’s at the end. That’s a good question, and the paper we’re citing doesn’t explain it at all, but so as to not keep it a mystery: it’s because anandamide is also called N–arachidonoylethanolamine. Still, anandamide does also get called “ANA”, but not in this paper, so we’ll stick to the “AEA” as used.

Now, with that out of the way…

Some highlights from their results:

• AEA rises throughout long-distance running : inexperienced long-distance runners, blood levels of AEA increased progressively at 14 km, 28 km, and around 43 km. Levels remained elevated even after 45 minutes of recovery.
• Running had a stronger effect than walking: when the same runners later walked the same route for the amount of time they had needed to complete the marathon, the increase in AEA was considerably smaller.
• Extreme distances produced a similar response: among ultramarathon runners completing 100 km, 160 km, or 230 km, AEA levels were significantly elevated after the race. Another endocannabinoid, 2-AG, also increased.

You can read this paper in full, here: Endocannabinoid dynamics across marathon and ultramarathon running: evidence from two field studies

But we know that not everyone will want to rush out to run a marathon, so…

Want to learn more about boosting your mood with exercise?

We recommend: Behavioral Activation Against Depression & Anxiety ← a tool for improving mood by changing behavior, creating a positive feedback loop to combat depression and anxiety—and exercise is one very good way to get started (albeit certainly not the only way!—see article for details)

On which note, yes, Running or yoga can help beat depression, research shows – even if exercise is the last thing you feel like

Lastly, there is, incidentally, One More Way Exercise Improves Mental Health ← and that’s often an overlooked one.

Enjoy!