Written by Bobby Zhu '26
Edited by Naphat Permpredanun '24
Mile 5: I’m feeling alright, my legs are fatigued but I’m keeping my original pace.
Mile 6: I’m starting to feel pretty tired, and my pace is dipping from its original pace.
Mile 7: All of a sudden, my legs feel alive again and I can resume the pace I had at the beginning of the run!!.
Now, how could my body miraculously ‘feel better’ at mile 7? Is it because of adrenaline? No, it was because my body reached a runner’s high phenomenon.
Runners can experience a feeling of elation, exhilaration, and painlessness associated with running for several miles because our bodies can create chemicals that reduce the amount of pain we feel. These chemicals are known as endocannabinoids, which are similar to the chemicals in cannabis(marijuana)[1]. Thus, by naturally producing chemicals found in marijuana, our bodies can regulate the amount of agony we experience while exercising.
Before endocannabinoids, many people believed that endorphins were the cause of runner’s high. The reason was that endorphins are part of the body’s larger opiate system This system binds to opioid receptors to induce an analgesic effect on the body. Thus, with an increase in plasma endorphins when exercising, it was assumed that the reduction in pain that runners experience upon achieving runner’s high was due to endorphins. However, recent research has shown that even though opioid receptors are blocked, a reduction in pain, as well as an increase in euphoria, were still observed [2]. Moreover, endorphins cannot cross the blood-brain barrier as endorphins are hydrophilic(water-loving) while the blood-brain barrier is lipophilic(lipid-loving) [3]. As a result, many researchers believe that endorphins are not the underlying cause of runner’s high. On the other hand, endocannabinoids are lipophilic which pass easily through the blood-brain barrier. Therefore, many scientists now look to endocannabinoids as the reason for runner’s high.
Similar to endorphins increasing during exercise, anandamide, a form of an endocannabinoid, increases dramatically during an intense exercise such as running [4]. This dramatic increase in endocannabinoids can help with the pain by suppressing the release of neurotransmitters and other signaling pathways in the cell that further promotes the suppression of other neurotransmitters. Therefore, signals like pain cannot be transmitted, and the body doesn’t ‘feel’ it. In addition, it also decreases the amount of inflammation by inhibiting certain cells, which leads to overall less pain [5]. As such, it is highly hypothesized that endocannabinoids have a role in runner’s high and the effects of lessening the agony of running.
The other component of a runner’s high is the euphoric sensation that accompanies the pain-free feeling; endocannabinoids have been observed to induce that feeling as well. Research has shown that endocannabinoids affect the frontolimbic region of the brain, which is an emotional processing center of the brain [6]. Upon activation of the region, a sense of euphoria is felt, which opioids like endocannabinoids enable by decreasing the affinity for specific binding sites in the emotion region of the brain. In fact, this induced euphoria is so potent that it helps athletes who were injured overcome their injuries and continue their sport, even if they may be at risk for further injuries [2]. Therefore, the addictive nature of runner’s high is extremely powerful and one of the best natural ways to continue with an otherwise grueling exercise.
The only downside to runner’s high is the ingredients needed to achieve it. Studies have shown that it may take up to an hour or two to reach that runner’s high because changes in brain chemicals were seen only after 3 miles of running [7]. Yet, in order for body to reach a sufficient level of endocannabinoids, our bodies need to be going at around 80% to 90% of our max heart rate, which means the beginning part of a run would be difficult as we need to push our bodies to a certain threshold before the euphoric and pain-free effects kick in. In addition, one needs about 8 hours of sleep a night in order for runner’s high to be properly achieved, most likely due to the body requiring more time to rest and recover before undergoing stress that running has on the body [8]. For many, a small spike in stress before events, like a race, could help with procuring a runner’s high, but chronic stress reduces the likelihood of it. While more evidence is needed to prove this point, it is possible that sleep deprivation leads to chronic stress on the body, which hampers our ability to produce endocannabinoids. However, running with music or running alongside a running buddy significantly helps with runner’s high and once you reach that runner’s high, it’ll be all the worthwhile.
While the history of runners’ high may be slightly misdirected by endorphins being the leading cause when, in reality, it was endocannabinoids, runner’s high is still very much a phenomenon that affects many. This feeling of weightlessness, of freedom, of exhilaration is extremely sought after and is one of the primary reasons that runners want to keep running. So, apart from the long-term health benefits of exercise and positive mental health benefits, running also induces short term benefits that help runners push through the pain of endless mileage, making running an enjoyable experience rather than a painful activity.
References
[1] Linden DJ. The truth behind 'Runner's high' and other mental benefits of running [Internet]. The Truth Behind 'Runner's High' and Other Mental Benefits of Running | Johns Hopkins Medicine. 2021 [cited 2023Apr3]. Available from: https://www.hopkinsmedicine.org/health/wellness-and-prevention/the-truth-behind-runners-high-and-other-mental-benefits-of-running#:~:text=You%20may%20have%20experienced%20it,of%20endorphins%20released%20during%20exercise
[2] Boecker H, Sprenger T, Spilker ME, Henriksen G, Koppenhoefer M, Wagner KJ, et al. Runner's high: Opioidergic mechanisms in the human brain [Internet]. OUP Academic. Oxford University Press; 2008 [cited 2023Apr3]. Available from: https://academic.oup.com/cercor/article/18/11/2523/291108
[3] Michael Siebers et al. Exercise-induced euphoria and anxiolysis do not depend on endogenous opioids in humans [Internet]. Psychoneuroendocrinology. Pergamon; 2021 [cited 2023Apr3]. Available from: https://www.sciencedirect.com/science/article/pii/S0306453021000470
[4] Wired to run: exercise-induced endocannabinoid signaling in humans and cursorial mammals with implications for the ‘runner’s high’ [Internet]. Journals.biologists.com. [cited 2023Apr3]. Available from: https://journals.biologists.com/jeb/article/215/8/1331/11332/Wired-to-run-exercise-induced-endocannabinoid
[5] Donvito G, Nass SR, Wilkerson JL, Curry ZA, Schurman LD, Kinsey SG, et al. The endogenous cannabinoid system: A budding source of targets for treating inflammatory and neuropathic pain [Internet]. Nature News. Nature Publishing Group; 2017 [cited 2023Apr3]. Available from: https://www.nature.com/articles/npp2017204
[6] Dalgleish T. The emotional brain [Internet]. Nature News. Nature Publishing Group; [cited 2023Apr3]. Available from: https://www.nature.com/articles/nrn1432
[7] Person. Is the runner's high real-and how do I get it? [Internet]. Reebok US. reebok; 2021 [cited 2023Apr3]. Available from: https://www.reebok.com/us/blog/451654-is-the-runners-high-realand-how-do-i-get-it
[8] Fetters KA. 5 steps to a runner's high [Internet]. Runner's World. Runner's World; 2022 [cited 2023Apr3]. Available from: https://www.runnersworld.com/uk/health/mental-health/a774668/endorphins-exercise/