What is Runner's High?
For many people, running starts off as a strenuous exercise that makes us uncomfortable. Your breathing becomes heavier, your heart pumps harder to move the oxygenated blood to your muscles and brain. Very quickly your legs start to ache and you feel like it is difficult to breathe and catch up.
But after a while at a pivotal moment, your body releases hormones called endorphins. Endorphins are commonly believed to be the source of the "Runner's High" where people may experience an elevated mood, less pain, and euphoria that lasts long after the run. However, recent research suggests that this common belief is wrong.
Endorphins are not the source of "Runner's High"
Recent research in the journal Psychoneuroendocrinology in April 2021 suggests that the euphoria after endurance exercises such as running does not rely on opioid (endorphin) signaling. In a double-blind, randomized, placebo trial, Naltrexone was used to block opioid (endorphin) receptors in participants. Despite being blocked, participants in the Naltrexone group experienced the same euphoria and reduction in anxiety while running as the placebo group, indicating that the runner's high does not require opioid signaling as previously believed. Moreover, the scientists also found high plasma levels of the endocannabinoids made in the body anandamide and 2-arachidonoglycerol, suggesting that endocannabinoids may be the source of the runner's high.
Older research in mice in PNAS of October 2015 also showed that opioids are not necessary to produce the state of runner's high in mice, but endocannabinoids were. The mice were given naloxone, an opioid antagonist, or cannabinoid 1/2 receptor antagonists and tested to determine anxiety levels and pain levels after running. After running, the naloxone group did not have any inhibition of the anxiolytic behavior, but blocking the CB1 receptor blocked the effect of the runner's high. They also found no differences between placebo and naloxone for pain, but blockage of CB1 or CB2 receptors did have an effect on mice. The scientists found that analgesia was mediated by both CB1 and CB2 receptors. In mice runner's high, CB1 receptors seem to mediate anxiety-like behavior while CB1 and CB2 mediate pain reduction.
Cannabinoids (CBD) and Runner's High
While we're seeing early research pointing us towards endocannabinoids as the source of the euphoria, pain reduction, and anxiolytic effects after running, this is an early step towards understanding the role of endocannabinoids and cannabinoid receptors in the human body.
We're excited to be in this field at such an exciting time when we may be redefining exercise and human physiology. In the meantime, we will continue to do research and work on improving our products to make the highest grade and science-based CBD product possible. As our understanding gets better, we may even try making a runner's high formula in the near future too :)
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