Runner’s High: 3 Biochemicals Associated With Runner’s High

Runner’s high is a euphoric feeling that spontaneously occurs in the human body—such as after long-distance running or other strenuous physical activities that lead to an increased [heart rate](https://www.masterclass.com/articles/heart-rate-zones-explained). Some researchers believe this physiological anomaly stems from brain chemicals activated in [fight-or-flight](https://www.masterclass.com/articles/fight-or-flight-response-explained) responses that have been passed genetically to modern humans from hunter-gatherer ancestors; however, the actual biological mechanism that creates this sense of euphoria is still debated in academic circles today. Not all experienced runners or athletes experience the sensation of runner’s high—even an ultrarunner who spends their career performing extreme distance runs may never have the pleasure of experiencing this phenomenon. The academic and research communities debate the exact science behind runner’s high, but in discussions of the phenomenon they usually mention certain biochemicals that the brain and body produce. Here are three of them: 1. __Endocannabinoids__: Biochemicals called endocannabinoids interact with the endocannabinoid system (a system in the body that might affect or regulate neural functions), much in the same way that the psychoactive cannabinoid derived from cannabis plants, tetrahydrocannabinol (THC), does. Researchers are still studying the effects of other naturally occurring endocannabinoids, like anandamide, to clearly define the role they play in creating or sustaining the feeling of euphoria associated with runner’s high. 2. __Endorphins__: The central nervous system produces neurochemicals called [endorphins](https://www.masterclass.com/articles/endorphins-explained), which flood the body during times of physical stress. These supportive chemicals act as opioid receptors to create potentially pain-relieving effects in runner’s muscles, similar to morphine or other opiates but to a lesser degree. Some research shows that endorphins might be too large to pass between the blood-brain barrier, a fact that would impact whether or not they are a component of a runner’s high state of euphoria. 3. __Leptins__: Hormones called leptins regulate hunger in the body. Results from a Canadian study published in 2015 showed that lab mice with lower levels of leptin had better aerobic endurance than mice with above average levels of leptin. This might suggest that the mice with lower leptin levels achieved a runner’s high in response to a biological motivation to seek out or chase food to satiate their hunger—although the study’s results were not conclusive. If you have a previous or pre-existing health condition, consult your physician before beginning an exercise program. Proper exercise technique is essential to ensure the safety and effectiveness of an exercise program, but you may need to modify each exercise to attain optimal results based on your individual needs. Always select a weight that allows you to have full control of your body throughout the movement. When performing any exercise, pay close attention to your body, and stop immediately if you note pain or discomfort. In order to see continual progress and build body strength, incorporate proper warm-ups, rest, and nutrition into your exercise program. Your results will ultimately be based on your ability to adequately recover from your workouts. Rest for twenty-four to forty-eight hours before training the same muscle groups to allow sufficient recovery. Get the [MasterClass Annual Membership](https://www.masterclass.com) for exclusive access to video lessons taught by the world’s best, including Joan Benoit Samuelson, Joe Holder, Serena Williams Stephen Curry, Simone Biles, Tony Hawk, and more. The runner’s high is a momentary sense of physical and mental elation during, or closely following, an intense aerobic exercise. Learn the science behind runner’s high and other health benefits associated with running.