Cross country runner Serena Lo (11) was close to halfway done with her race. She felt exhausted and drained, but still motivated to keep going. She was well aware of the pain in her legs, but she wasn’t going to stop. She was going to continue running until the finish line and she was going to feel incredible once she got there. 

David Linden, professor of neuroscience at Johns Hopkins University, explains that this euphoric feeling is caused by your body releasing endorphins and endocannabinoids, both which are biochemical substances produced naturally in the body, and one way to experience this is through exercise that tests endurance, like running.

Lo has been competitively running since the fourth grade, and she first felt the adrenaline rush, also known as a “runner’s high,” when she began to seriously train for races.

“Personally, it feels good and refreshing,” Lo said. “It’s like a big weight is lifted off my shoulders and my breathing also becomes a lot clearer. My body feels really light and energized, and my mood is always happier and in a better state after running.”

According to Linden, the endorphins are a naturally occurring opiate that mimics the feeling of morphine when released into your brain, and that combined with endocannabinoids is what causes a feeling of ecstasy.

 However, Linden explains, it is unlikely endorphins contribute much to the euphoric feeling. 

“Research shows that endorphins do not pass the blood-brain barrier,” Linden writes in his article, The Truth Behind ‘Runner’s High’ and Other Mental Benefits of Running. “Unlike endorphins, endocannabinoids can move easily through the cellular barrier separating the bloodstream from the brain, [which helps to] promote short-term psychoactive effects such as reduced anxiety and feelings of calm.”

Endocannabinoids like these are released in higher quantities when your body is put under more physical stress, which is what prolonged exercising that tests endurance can achieve. 

“After going on long runs of seven miles or more, it’s more likely that I feel runner’s high since my body gets worked for a prolonged amount of time,” Lo said. “I still sometimes experience runner’s high after a short run, though it isn’t always as pronounced.

Anastasia Papina (10) also began to experience this euphoric feeling after she started to run more due to the quarantine.

“I started running two to three miles every day at the start of quarantine and I first noticed [runner’s high] after a week of running,” Papina said. “After my stamina got better, I’d feel [the high] after every run. I would feel really happy with myself, my body, and how my run went.”

In addition to the feel-good hormones Lo and Papina feel when running long-distance, the “high” they experience when running motivates them to push themselves harder on their next run. 

“The feeling of accomplishing a run and experiencing runner’s high is always a good thing,” Lo said. “In general, I always try to make the most of every time I can run since I know that there is always room for improvement as I continue to perform and run to the best of my abilities.”

Papina also appreciates the way exercising and experiencing the endorphin-rush makes her feel and how it affects her throughout the day.

“After a long run I have more energy pushing myself to be more productive in the day,” Papina said. “Days I don’t run, it’s harder for me to sleep and I wake up later. Experiencing the high has changed the way I view exercising and running.”