According to a new study, runners have something in common with stoners that might surprise you. New evidence has shown the runner’s high you feel after a long workout session is actually caused by a neurotransmitter that’s also associated with marijuana use.
Popular Science reports that scientists have long assumed that the pleasant feeling you get after a long workout, often called a runner’s high, was due to endorphin release. Endorphins are the body’s natural pain killer, and the assumption was that they also triggered the feelings of relaxation and euphoria associated with a runner’s high.
That assumption fell apart in the face of recent research.
According to a new study, another chemical that is released during exercise may actually be responsible for the runner’s high. The chemical is anandamide, which is a neurotransmitter sometimes referred to as “the bliss molecule.”
Unlike endorphins, anandamide can cross the blood-brain barrier. When it does, it bonds to the cannabinoid receptors in the brain. And in the same way that morphine binds to receptors meant for endorphins, cannabinoids like THC bind to receptors meant for anandamide.
While there seemed to be some connection between a runner’s high and a stoner’s high, it was only conjecture until scientists put it to the test in a study.
According to the Daily Mail, the study involved mice that were trained to run on a treadmill. The mice were then split into two groups. One group was allowed to rest, while the other ran for another five hours.
Researchers then tested for signs of a runner’s high by using various methods to determine how anxious and tolerant of pain each group was.
The mice that spent five hours running showed less anxiety and more tolerance for pain, so the researchers concluded that they were capable of experiencing a runner’s high similar to that observed in humans, dogs, and other animals.
Once that was established, one group of mice was dosed with endorphin blockers and the other with cannabinoid blockers. The mice were then tested after another running session, and the group that received endorphin blockers showed lowered anxiety and increased tolerance for pain compared to the group that received anandamine blockers.
The conclusion was that cannabinoids, which would be anandamine in humans, are instrumental in the high felt by runners. However, they admitted that while they tested for anxiety, they could not test for the sense of euphoria typically experienced by both stoners and runners.
According to the researchers, “Euphoria is a highly subjective feeling that may be difficult to model in mice.”
Popular Science reports that this isn’t the first time a study has connected the highs felt by runners and stoners, and that some studies connecting endocannabinoids to a runner’s high have even involved humans. However, this study was the first time that endorphins were taken out of the equation.
Iñigo San Millán, director of sports performance at the University of Colorado, told Shape that marijuana has an adverse effect on cardiovascular performance due to “ergolytic properties,” but that runners might see benefits from smoking anyway.
“Obviously your mental state plays a role in how well you perform,” San Millán told Shape. “And in certain situations when reducing anxiety or pain is beneficial, marijuana may be helpful despite its ergolytic properties.”
Does the fact that stoners and runners feel the same high change your mind, if you had a negative outlook on marijuana before? Or if you already smoke marijuana, do you think that the idea that you could get a free high from running might get you to exercise more?
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