Let’s be honest: running is fundamentally a senseless activity.
Heading out in the cold, the heat, the rain, or that damp mist that clings to your skin, just to put your body through a kind of stress that most reasonable people avoid like the plague.
And yet, we do it.
And sometimes—just sometimes—during this seemingly masochistic process, something strange happens.
There’s a moment, in the midst of a long, steady run, when the world dissolves: your legs move on their own, your breathing becomes deep but light, and your mind empties, as if someone hit “mute” on the background noise of life. A strange wave of well-being, a mental clarity that makes everyday problems feel small and far away, a kind of light, clean euphoria.
They call it the runner’s high.
The Endorphin Myth
For years, we happily bought into the myth of endorphins—a simple and charming story, almost cinematic.
You run, your body suffers, and to keep you from collapsing in pain, your brain releases these substances—endogenous opioids—basically morphine’s homemade cousins. A natural painkiller that, as a lovely side effect, gives you a hit of euphoria.
Too bad, as with many things that sound too good to be true, it’s an oversimplified story.
Science—which has an annoying habit of ruining good stories with facts—started raising doubts.
The main problem is logistical: endorphins are bulky molecules, like trying to squeeze a semi-truck through a medieval town. They have a hard time crossing the blood-brain barrier—the brain’s ultra-selective gatekeeper against unwanted guests.
Enter the Endocannabinoids
This is where the real stars of our story come in: leaner, more agile compounds far better suited to sneaking into the exclusive party that is the central nervous system—endocannabinoids.
Yes, you read that right. Cannabinoids. Substances your body makes that are surprisingly similar to the active compounds in cannabis.
The most famous is anandamide, named after the Sanskrit word ananda, meaning “inner bliss.”
I think you get the idea.
Unlike clumsy endorphins, anandamide and its cousins are lipophilic, which means they easily cross the blood-brain barrier.
During prolonged physical activity, levels of anandamide rise significantly, helping reduce anxiety and create that euphoric feeling every long-distance runner knows so well.
Scientific Proof
Need solid evidence?
Some German researchers gave runners a drug that blocks opioid receptors—essentially making endorphins useless.
The result? Participants still felt the anxiety-reducing, euphoric effects of runner’s high.
But when cannabinoid receptors were blocked, the effect disappeared completely.
Animal studies back this up: blocking endocannabinoid receptors eliminates the euphoric effects of exercise, while blocking opioid receptors does not.
How Much and How Long to Feel It
By now, your curiosity is probably piqued.
So when does this “high” kick in?
Both the intensity and duration of exercise are key.
To trigger a significant release of endocannabinoids, you need at least 30–45 minutes of moderate aerobic activity.
That’s why runner’s high is more common among distance runners than those who do short bursts or high-intensity workouts.
Beyond Euphoria: Mental Benefits
Runner’s high isn’t just a feel-good buzz—it has real mental health benefits.
The rise in endocannabinoids during exercise is linked to lower levels of anxiety and depression.
This makes running a powerful natural ally for psychological well-being.
So the next time you’re out there, maybe in the middle of a long run, your legs moving effortlessly, a playlist in your ears, and you feel that strange, indescribable sense of peace—know that it’s not just your willpower.
It’s your body creating its own dose of bliss—a little chemical magic reminding us that maybe, just maybe, there really is something deeply meaningful in this “senseless” act of running.