Have you ever heard someone say they are addicted to working out, or running? For some this may be an odd statement since not all of us find workouts enjoyable. The truth is, is that you can feel a type of high from an intense workout and scientist have a new theory on the cause.

Originally it was thought that the release of endorphins is what caused the euphoric feeling achieved through an intense workout, which reduced your body’s feeling of pain and so you would get the high feeling. Scientists now think that the high is caused by a chemical called endocannabinoid. It is thought that this chemical is like your body’s self-made marijuana and even has a similar effect that the drug has on your pain, mood and even your hunger.

The studies on the endocannabinoid hormone are still only being done on mice though and the effects on humans are not yet known. In one study, it was found that mice who ran on their wheels were far less anxious and handled pain better, whereas the mice who had their endocannabinoid system blocked with drugs were more anxious and were even more sensitive to the same pain. This led researchers to the conclusion that cannabinoid receptors are important to the explanation of the runner’s high.

This August, scientists at the University of Montreal released their findings on another hormone called Leptin, given the nickname the “Satiety Hormone” because it is what tells your body that you have enough energy and food to function. Scientists believe that in the middle of a workout, your leptin levels fall, which sends a signal for hunger to the pleasure center of the brain and creates the rewarding effects of running. A study done on mice whose genes had been changed to lack leptin-sensitive proteins called STAT3, found that they actually ran twice as much as normal mice due to the lack of feeling satisfied with their workout.

Sources: Washington Post, Cell



“working out” (expression) : exercising
odd (adj.) : strange
high (adj., n.) : good or euphoric feeling (usually used when referring to drug use)
endorphins (n.) : group of hormones in the brain
marijuana (n.) : cannabis, especially when smoked
handled / to handle (v.) : to deal with a situation
to function (v.) : to be able to do activities
lack (n.) : being without enough of something
twice (adj.) : two times