Runner's high is an elusive state where the drudgery of pounding pavement transforms into something akin to a chemically enhanced experience. Some runners seem to achieve it on most runs, while others rarely or never feel it. Even professional athletes sometimes doubt its existence. This variation stems partly from individual differences in brain chemistry and partly from training methods.
What Causes Runner's High?
Contrary to popular belief, runner's high is not primarily about endorphins. According to Dr Daya Grant, a neuroscientist and mental performance consultant, “The runner’s high seems to be caused by an orchestra of neurochemical changes across several brain systems, including the opioid system (of which endorphins are a part) and the endocannabinoid (eCB) system. While endorphins are involved, they don’t seem to be the main drivers; that central role belongs to the eCB system.”
Endocannabinoids are the body's internal version of cannabis compounds, produced to manage pain, forget stressful events, and prevent overexcitation of brain cells. The eCB system was discovered only in the 1990s, after the concept of runner's high was first discussed, which explains why the endorphin theory took hold. Recent animal research suggests that endorphins cannot cross the blood-brain barrier, whereas endocannabinoids can and appear to be the main mechanism for key aspects of the experience.
How to Boost Your Chances
Sustained Moderate-to-Hard Aerobic Effort
To reliably trigger runner's high, aim for sustained moderate-to-hard aerobic effort. High-intensity interval training can produce similar neurochemical changes but may not always lead to subjective feelings of euphoria and reduced anxiety.
Incorporate Nature and Play
Exercising in nature offers well-documented psychological benefits and may enhance the experience. Dr Trish Jackman, associate professor in sport and exercise psychology at the University of Lincoln, notes, “One benefit of running on trails is the element of play – jumping over tree roots or navigating rough terrain – which is physically beneficial and may help access flow states.”
Find the Right Challenge Level
Flow state, often confused with runner's high, involves being fully immersed in an activity where skills match the challenge. It can occur independently but often accompanies runner's high. To enter flow, run at a pace that challenges you without pushing too far outside your comfort zone.
The Role of Other Neurochemicals
Dopamine, the “feelgood” hormone, increases during long runs and peaks around the 60-minute mark, enhancing cognition and motivation. Norepinephrine, driving fight-or-flight responses, rises significantly near maximum anaerobic threshold (e.g., during interval training), helping with focus and alertness. Together, these effects contribute to feeling good during workouts without the crash typical of external stimulants.
Why Some Never Experience It
One leading theory is that some people have enzymes that clear endocannabinoids too quickly for them to have a noticeable effect. However, many runners who never experience the high still learn to love running for the little wins, flow states, and sense of achievement. Like a half-marathon medal, runner's high is nice when it happens, but it's not the only reason to run.
Runner's High in Other Sports
Similar effects have been documented in cyclists and rowers. The rarity in other sports may be due to the difficulty of achieving sustained moderate-intensity effort. For example, cyclists who pedal hard uphill then freewheel downhill may not stay in the optimal zone. Interval training also may not hit the sweet spot for a proper runner's high, as it involves bursts followed by rest.
Can You Get Addicted to Exercise?
Regularly achieving runner's high may train the brain to associate effort with reward, enhancing motivation to keep running. While there is evidence that running alters brain structure over time (e.g., increasing hippocampal volume), direct evidence linking repeated runner's high episodes to structural changes is lacking. However, running builds stress resilience, and experiencing runner's high repeatedly can reinforce the habit.
