Is Runner's High Even Real?

When Kile Putman reached mile 7 of his first marathon four decades ago, he was on the verge of quitting. Despite six months of rigorous training and being in peak physical condition, he was overwhelmed by an unexpected fatigue early in the race. This exhaustion persisted for the next 10 miles (16 kilometers) as he pushed through, running alongside a group of similarly determined athletes.

Then, something shifted. The overwhelming burden that had slowed him down and caused muscle cramps suddenly vanished. He felt an inexplicable lightness, as though he were gliding. His speed increased, and he began to outpace the others. The run transformed into something extraordinary. Overcome with emotion, he started crying—not out of sorrow, but from an overwhelming sense of joy that remains indescribable to this day. Could this have been runner's high?

Is Runner's High All in Your Head?

Putman, a USA Track & Field-certified coach, and I are jogging through a neatly maintained suburban neighborhood in Alabama, weaving around clouds of freshly cut grass scattered by loud leaf blowers. Our conversation revolves around the concept of "runner's high"—a blend of euphoria and tranquility some runners claim to experience. It’s then that he shares the emotional surge he felt during his debut marathon.

"I’m not sure if it was a runner's high or just some overwhelming emotion," he admits. "Perhaps it was purely psychological." Given Putman's natural skepticism, I decided to consult Margaret Smith, Ph.D., a sports psychologist and performance coach based in Birmingham, Alabama, who specializes in the mental health of athletes.

"Absolutely, I believe it’s real," she asserts. "As a runner myself, I’ve had those incredible days when it happens, and it feels absolutely amazing."

If you ask runners whether they’ve ever felt a runner's high, many will look skyward and reminisce about those rare instances when they were so deeply engrossed in their run that their bodies seemed to move effortlessly, almost as if on autopilot.

Smith refers to this phenomenon as the "flow state," a term coined by Hungarian-American psychologist Mihaly Csikszentmihalyi after studying athletes, musicians, and artists to understand what brings them joy. He found that during peak performance, these individuals entered a deeply focused mental state where their actions felt effortless and natural.

Could this state of mindful immersion be the key to runner's high for athletes? Smith suggests it might be. Alternatively, the mere belief in experiencing a runner's high could make it feel real. "Social psychology shows that perception heavily influences reality," she explains. "If I believe something is real, it impacts my behavior and how I interpret experiences."

Is There a Physical Explanation for Runner's High?

The concept of runner's high has been a hot topic since the 1970s running craze, according to Jack Hasson, M.D., a passionate runner and pulmonologist at the University of Alabama at Birmingham. Researchers, many likely runners themselves, attributed this sensation to the flood of endorphins released during intense physical activity as the body responds to stress.

Endorphins are neurotransmitters that interact with the body's opiate receptors, producing a pain-relieving effect. Hasson explains that this process not only dulls physical discomfort but also induces a euphoric state similar to the effects of morphine.

While this explanation seemed plausible, morphine-induced euphoria differs significantly. Morphine, an opioid, stimulates the release of dopamine, a neurotransmitter that blocks pain and generates pleasurable sensations. However, Hasson notes that morphine also causes drowsiness, which contrasts sharply with the energizing and alert state of a runner's high.

Instead, runner's high is often described as a profound sense of unity, spirituality, or tranquility, he explains. This sensation is more akin to the effects of cannabis, as described by those who have used marijuana. (Hasson himself has never tried it.)

Research supports this idea. A 2015 German study using mouse models revealed that running activates the body's endocannabinoid system, which produces endocannabinoids—natural compounds similar to cannabis. These chemicals are known to alleviate anxiety and improve mood. In fact, many people use cannabis to self-medicate for anxiety relief, as researchers have noted.

"Some experts now believe that this is the true mechanism in the brain. It’s more about a spiritual sensation, similar to the effects of cannabis, rather than the pain relief and calmness provided by morphine or opioids," Hasson explains. As a runner himself, this explanation resonates more with his personal experiences.

"I’ve run everything from 5Ks to ultramarathons, and I’ve felt that sense of spirituality, peace, and deep relaxation," he shares. "That’s why I lean toward the idea that runner's high is more likely tied to cannabis-like effects rather than opioid-related ones."

Addicted to Runner's High

There must be something truly compelling about runner's high, or else why would people consistently endure the physical demands of running multiple times a week, sometimes even daily?

"This could explain why people develop a sort of addiction to running," Hasson remarks. Similar to the effects of opioids or cannabis, runner's high activates the brain's reward system. The brain is wired to seek out that pleasurable sensation again, though, much like with opioids, the subsequent highs are often less intense, which can fuel addictive behavior.

Whether it’s the cannabis-like endocannabinoids, the opioid-like endorphins, or a combination of both, achieving that euphoric state during or after a run is a cherished reward for many, even if it occurs infrequently.

For my running companion Putman, if he truly experienced runner's high during his first marathon 40 years ago, it never happened again. Yet, he’s never stopped pursuing that extraordinary sensation. "It’s what kept me coming back to marathons," he admits.

However, as I mentioned, Putman remains a skeptic. I remind him of that memorable day during marathon training when we ran the Vulcan 10K course in Birmingham three consecutive times, totaling over 18 miles (29 kilometers) under a cloudy sky, finishing with a long downhill stretch. "You didn’t feel a high then?" I ask. Because, honestly, I certainly did.

I notice him shaking his head in my peripheral vision. "No, that was just a solid run," he replies.

Hasson mentions that environmental factors might contribute to a runner's high, but he’s skeptical that they’re the sole explanation.

"Sometimes, everything aligns perfectly for a run. The weather is ideal, and you’re in top form, leading to a euphoric feeling," he explains. "But I don’t believe that’s the norm during a runner's high. There are days when conditions are terrible, yet I run well and finish feeling amazing."