ALTANTA (CBS Atlanta)– The “high” you get after running may be linked to the same high you get from smoking weed, according to a new study.
Researchers found the post-exercise feeling of euphoria provides a similar effect as smoking marijuana due to the brain’s cannabinoid receptors that relieve pain, as reported by Daily Mail.
University of Hamburg and University of Heidelberg researchers studied cannabinoid receptors in mice after they ran. Previous research indicates that the pleasant feeling associated with a runner’s high is due to raised levels of beta-endorphins.
However, the new findings suggest that these endorphins are actually too large to get through the blood-brain barrier and that it’s more likely the feeling is associated with the cannabinoid receptors. These receptors can affect appetite, pain, mood, and memory.
“Running exercise increases blood levels of both beta-endorphin (an opioid) and anandamide (an endocannabinoid),” the researchers wrote.
Researchers tested the theory by conditioning a group of mice to run on a treadmill, they were then separated into two groups. One group ran on the treadmill for five hours while the other group stayed inactive.
Both groups were then evaluated for reduced anxiety by seeing how the mice behaved in the dark and by testing their tolerance for pain.
A second experiment used all the same factors, but also gave the mice endocannabinoid and endorphin antagonists that blocked the effects. This time the mice who ran showed no results of a runner’s high.
“[This shows] for the first time to our knowledge that cannabinoid receptors are crucial for main aspects of a runner’s high,” study authors note.