Understanding the Runner's High - The Science Behind the Feeling

Runner’s high is an exhilarating sensation that can motivate people to exercise more. Additionally, running can bring numerous health advantages including weight loss and reduced risks of certain diseases. 

The runners high is thought to be caused by endorphins, neurotransmitters that produce pleasurable feelings and relieve pain, but new research indicates that endocannabinoids – similar to cannabis’ THC molecules – play an integral part of it too.


Runners often report feeling exhilarated and almost invincible after their runs, leaving them wondering what caused this positive sensation. Scientists have long associated this high with endorphins – natural chemicals produced during exercise that bind with opioid receptors in the brain to produce feelings of pain relief and pleasure. Simultaneously, it improves mood and helps runners endure lengthy, strenuous workouts. 

Second-Guessing Endorphins as the Cause?

Endorphins are released when performing exercise of any intensity. However, when coupled with strenuous activity they have been seen to play a major role. Therefore, they have long been thought to be responsible for creating runner’s high. But new research indicates otherwise, and shows how these molecules may not actually cause this sensation of fulfillment and happiness after exercise. 

Instead, the cause may lie with endocannabinoids – lipids produced naturally by your body that act on the same system in the brain affected by tetrahydrocannabinol, the active ingredient found in marijuana. When running, your body releases these endocannabinoids which produce similar euphoric feelings as endorphins do. 


Researchers discovered that exercise not only releases endorphins, but also releases endocannabinoids – another class of lipid chemicals known to affect mood. They are like endorphins, but with greater potential to cross over blood-brain barriers. 

Scientists have found elevated levels of endocannabinoids correlate to increased feelings of well-being after moderate endurance exercise. Endorphins act by binding to mu opioid receptors of the nervous system to produce painkilling effects. In contrast, endocannabinoids bind to CB1 and CB2 cannabinoid receptors of the brain, producing various effects such as relaxation and hypoalgesia-decreased sensitivity to pain. 

Studies have also indicated that these substances increase dopamine production within our bodies resulting in feelings of reward and pleasure. More research is suggesting that endocannabinoids play a bigger role in the feeling of the runner’s high than previously expected. 

One finding found that mice injected with antagonists (molecules that block cannabinoid receptors) that deactivated CB1 and CB2 receptors were unable to experience its joys of running. In other words, if the mice had CB1 and CB2 receptors, they should have felt a runner’s high.

The Role of Dopamine

Exercise also triggers the release of dopamine, a neurotransmitter associated with feelings of reward and pleasure – similar to when winning the lottery, orgasming or eating chocolate sundaes! Over time, your brain learns to release these chemicals automatically – giving runners their “runner’s high”. 

Dopamine may or may not play a significant part of runner’s high, but its existence does suggest that runners feel better after finishing their run and enjoying post-run recovery. Non-runners might find it hard to understand why experienced runners seem so happy when their run is complete. But it might explain why experienced runners seem happy to finish up. 


Though many associate runner’s high with running, other aerobic activities can bring on similar sensations, including swimming or strenuous biking. Many endurance athletes experience adrenaline to power through their workout. For runners, the experience typically lasts several miles into the workout itself or immediately afterwards. 

Adrenaline attaches itself to receptors in your liver that break down larger sugar molecules into more digestible forms – glucose. Furthermore, adrenaline stimulates heart cells to beat faster, widening blood vessels that direct more blood toward major muscles or limbs. Furthermore, it sometimes causes you to sweat more profusely than normal! 

Fight or Flight - A Runner's Friend?

However, adrenaline has a bad reputation…and it might be unwarranted. It’s a stress-fighting and fitness-inducing steroid. It’s purpose (as you may well know) is to help you fight or flee from danger, which is also why you may feel invigorated after physical exertion. 

The physical intensity that your body undergoes when running fast or going for a long run can trigger your body to release adrenaline. Since your body can’t tell the difference between fleeing from a threat or just casually running, adrenaline is released. This also explains why you may feel like you get stronger or faster as you go about your run. 

A Final Recap

Understanding the complex interplay of these chemicals sheds light on why running can be so fulfilling and addictive for many individuals. This intricate interplay underscores why running is not just a workout but a holistic experience promoting mental and physical well-being. 

Key Takeaways: 

● Runner’s high is a euphoric feeling associated with running, motivating people to exercise more and offering numerous health benefits. 

● Endorphins, natural chemicals produced during exercise, bind with opioid receptors to produce feelings of pain relief and pleasure, contributing to the runner’s high. 

● New research suggests that endocannabinoids, similar to THC in cannabis, also play a significant role in the runner’s high by acting on cannabinoid receptors in the brain. 

● Dopamine, a neurotransmitter associated with reward and pleasure, is released during exercise and contributes to the positive feelings experienced after running. 

● Adrenaline, a stress-fighting steroid, is released during intense physical activity like running, contributing to the invigorating sensation known as the runner’s high.

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