The line between suffering and bliss is razor thin when it comes to endurance sports. You push through the burn, sweat dripping in your eyes, lungs screaming for mercy — and then suddenly, something flips. The pain quiets down. Your body feels light. Your mind clears. You’re not just running anymore, you’re groovin – that's the runner's high.
Some people never catch it, others only feel it after they stop, but when it hits during movement, it’s like your body has unlocked a hidden performance system. Scientists now know it’s not about endorphins (the old theory) but rather, your body’s endocannabinoid system — the same natural system cannabinoids like CBD and THC tap into.
In this article, we’ll break down the evolution of the runner’s high, the science that makes it possible, and why this legendary state of euphoria is more than just a runner’s myth.
What Exactly is the Runner’s High?
The runner’s high is often described as “a short-lasting psychoactive state during or after endurance exercise characterized by euphoria, reduced anxiety, and decreased pain perception.”
IYKYK… but if you don’t know… imagine your brain slamming the mute button on all the noise — the deadlines, the to-do lists, the group chat chaos — and suddenly you become entranced with your feet hitting the pavement. For a little while, you’re free to focus on yourself.
When it lands, the runner’s high feels like you are unstoppable. Happiness takes over, your mind chills, and some even say they feel more connected to the world buzzing around them. Physically, your body feels lighter, almost tricked into forgetting it’s tired, so you can keep pushing without the grind dragging you down.
That combo of mental clarity + physical relief is why the runner’s high is one of the most hyped-up rewards in sports — elusive, yes, but addictive once you’ve tasted it.
Which begs the question: why would evolution wire us with this hidden perk for long, sweaty miles? The answer might go all the way back to our ancestors.
Evolution and the Runner’s High
Long before gyms and marathons, our ancestors relied on persistence hunting for survival — literally running animals into exhaustion. No claws, no fangs, no speed advantage. Just sweat and stubbornness. Humans are freakishly good at pacing ourselves for hours, and that endurance is what kept us fed.
Some researchers think the runner’s high is a leftover survival perk from those hunts. The euphoria isn’t just a fun bonus — it’s your body’s way of bribing you to keep going when everything hurts. Along with the mental lift, your system dials down pain, basically handing out natural painkillers so you can push through.
For a long time, endorphins got the credit. But the real drivers are endocannabinoids — your body’s own cannabis-like compounds that spark the same system THC and CBD tap into.
Endocannabinoids and The ECS
The endocannabinoid system (ECS) is a built-in balancing network that helps regulate essential functions like mood, pain, appetite, sleep, and immune response. At its core are two main receptors that interact with endocannabinoids and cannabinoids: CB1 and CB2.
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CB1 receptors hang out mostly in your brain and nervous system, where they influence things like mood, memory, coordination and how we process pain.
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CB2 receptors are spread throughout the body, especially in your immune system, where they help control inflammation, immune response and recovery.
If you think of the ECS as your body’s control panel, CB1 and CB2 receptors are two of the biggest switches – always working to keep you balanced, calm and moving forward.
Two of the most important (and most studied) endocannabinoids that interact with these receptors are anandamide and 2-AG (2-arachidonoylglycerol):
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Anandamide, nicknamed the “bliss molecule” — is linked to feelings of calm, euphoria, and motivation. It binds to both CB1 and CB2, but more strongly influences CB1, especially in mood regulation and stress relief. Research suggests Anandamide is the most prominent endocannabinoid responsible for inducing the “runners high”.
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2-AG is known to be the most abundant endocannabinoid in the body. It binds to both receptors and plays a central role in appetite regulation, pain management, stress recovery, and especially inflammation control.
Here’s where cannabis steps in:
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THC mimics anandamide by binding directly to CB1 receptors, producing that familiar “high.” But THC is far stronger and lasts much longer than your body’s natural endocannabinoids, which is why some athletes experiment with cannabis to enhance mood, reduce discomfort, or tap into flow during training.
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CBD works differently. It doesn’t directly mimic 2-AG or bind strongly to CB1 or CB2. Instead, it helps regulate the ECS by slowing the enzymes that break down endocannabinoids like 2-AG and anandamide. This means your body’s own “bliss chemicals” stick around longer, supporting balance, recovery, and resilience without producing a high.
For years, endorphins were hogging the credit for producing the runner’s high. But endorphins can’t easily cross the blood brain barrier, which means they don’t explain the euphoric rush that comes from endurance movement. Today, researchers agree the real MVPs are endocannabinoids, especially anandamide, that drive that blissful “I could go forever” feeling.
Even with this built in system for producing runner's bliss, not everyone experiences it the same way…
Factors that Influence the Runner’s High
As we now know, the ECS plays a central role in the runner’s high. However, not everyone experiences this flow state the same way. That’s because it depends on a mix of factors:
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Duration & Intensity: Science suggests there is a sweet spot for hitting the runners high. It usually takes about 30–60 minutes of steady effort at a moderate-to-intense pace — think 60–80% of your max heart rate. Go too easy and your body won’t trigger the endocannabinoid flood. Push too hard and stress hormones might override the bliss. The high lives in that middle zone where you’re working, but still groovin’.
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Fitness Level: The fitter you are, the harder your body might make you work to hit that sweet spot. Beginners may stumble into the high sooner but peter out faster, while seasoned athletes sometimes have to push deep into the pain cave before the chemistry pays out.
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Individual Physiology: Some folks are genetically blessed with the ability to pump out bliss chemicals easily; others might need more time, better sleep, or less stress in the mix before things click. And some unlucky people may never get there naturally (that's where cannabis comes in).
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Mental State & Environment: How you feel going in — and whether you’re zoning out on a forest trail or dodging strollers on a city sidewalk — can shape just how strong the high hits.
Because of these variables, the runner’s high remains elusive. Some athletes have turned to THC as a way to spark similar effects earlier in their workouts — essentially stacking modern cannabis science on top of an ancient survival mechanism.
Tap into Your Groov
The runner’s high is and will likely be an evolving topic in the scientific community, but interest in it is rapidly growing. It’s clear that more attention needs to be paid to both the ECS, endocannabinoids and the role that they play in our everyday lives.
Next time you exercise, keep an eye on the clock, your heart rate and mental state. Spend some time thinking about your mood, how your body feels, and whether or not you’re experiencing a runner’s high. Try new forms of exercise and don’t be afraid to find your own “high.”
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