The runner's high, that elusive state where pounding the pavement transforms into a chemically enhanced experience, is a phenomenon that has puzzled athletes and scientists alike. Some runners experience it almost every run, while others rarely feel it. New research sheds light on the neurochemical mechanisms behind this euphoric state and how to increase your chances of achieving it.
Contrary to popular belief, endorphins are not the primary driver. Dr. Daya Grant, a neuroscientist and mental performance consultant, explains: "The runner's high seems to be caused by an orchestra of neurochemical changes across several brain systems, including the opioid system 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, helping manage pain, reduce stress, and prevent overexcitation of brain cells. The eCB system was discovered only in the 1990s, after the runner's high was first described, which is why the endorphin theory persisted. Recent animal studies suggest endorphins cannot cross the blood-brain barrier, while endocannabinoids can, making them key to euphoria and reduced anxiety associated with the runner's high.
Another important distinction is that runner's high differs from flow state, though they often co-occur. Flow is characterized by complete immersion where skill matches challenge, while runner's high involves euphoria and altered time perception. Dr. Trish Jackman, associate professor at the University of Lincoln, notes: "Sometimes we think runner's high needs to be euphoria, whereas flow is more about body and mind feeling at one, with less awareness of fatigue."
To boost your chances of experiencing runner's high, focus on sustained moderate-to-hard aerobic effort. High-intensity interval training may produce similar neurochemical changes but doesn't always lead to subjective euphoria. Running in nature can enhance psychological wellbeing, and navigating trails adds an element of play that may facilitate flow.
The runner's high isn't exclusive to running—cyclists and rowers have reported similar effects. However, it's more common in activities requiring sustained effort rather than bursts of intensity. Professional athletes may rarely experience it because their training often involves either very high intensity or easy miles, missing the sweet spot.
While regular runner's high may not directly alter brain structure, there's evidence that running can increase hippocampal volume over time, benefiting learning and memory. The key is consistency and finding the right balance of challenge and enjoyment.