If you work out regularly, then you probably have experienced “runner’s high”– a feeling of euphoria combined with reduced anxiety and pain and not exhaustion and deliriousness. Although this is an amazing benefit of many provided by exercise, you may be surprised to learn that your endocannabinoid system is one of the main mechanisms at work for causing this natural mood-enhancing effect.
In short, the endocannabinoid system is a biological system found within all living vertebrates that regulates a number of functions including mood, appetite, pain, etc. in the body. Beyond exogenous cannabinoids found in cannabis, here you can find endogenous cannabinoids called endocannabinoids — natural chemical compounds mostly made up of lipids, or fat molecules produced by cells in your body.
Similarly to cannabis’ cannabinoids like CBD and THC, they bind to and activate cannabinoid receptor sites found throughout your body: mainly the nervous system and immune system which can lead to widespread health benefits including responding to illness, injury, and stress, illness, and injury, thus, keeping you healthy and happy. No matter the task, the goal of your endocannabinoid system is always the same: to keep your body in a balanced state, which is also known as homeostasis.
So, how does this all tie in with exercise?
For a long time, science believed that the phenomenon of “runner’s high” had everything to with the increase of endorphins — molecules that release mood-enhancing chemicals called opioid peptides that resemble synthetic opiates and work as analgesics to create feelings of well-being — in the blood. But, this was not the case.
While endorphins levels do indeed spike in the brain following physical activity, current research has found that this has little to do with their post-workout buzz, discovering that not endorphins, but endocannabinoids such as anandamide were responsible for producing this pleasant experience that comes on as a result of physical activity — in mice at least. Endocannabinoids were small enough to pass through the blood-brain barrier of the mouse models when released in the blood stream. On the other hand, endorphins were too big and were unable to make the full travel.
Furthermore, research has also found that higher levels of endocannabinoids were present in the blood of both people and animals after exercise.
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Fuss, Johannes, et al. A runner’s high depends on cannabinoid receptors in mice. Proc Natl Acad Ski U S A. 2015; 112(42): 13105-13108