Exercise is known to have a positive effect
on mental health, with active people less likely to experience depression, anxiety, and other mental health conditions. Along with its positive influence on long-term behaviour, exercise has also been associated with immediate feel-good vibes. If you're an enthusiastic jogger, you may have experienced the famous runner's high. Marked by feelings of euphoria, this natural high has
long been attributed to endorphins. According to a recent study, however, endogenous cannabinoids may actually be responsible.
The runner's high is a subjective euphoric
feeling that can happen both during and immediately after exercise. While
physical exertion often causes discomfort and even pain, the lucky few also get
a pronounced feeling of delight. When you run, you're flooding your body and
blood with endorphins. As the body's self-produced opiates, endorphins produce
a variety of chemical changes that are often interpreted as pleasure and joy.
Endorphins are a natural pain reliever, which helps you to run for longer and
feel better when you're finished.
Contrary to popular belief, however, the
chemical nature of the runner's high is not entirely down to endorphins. New
research points to another type of molecule, with endocannabinoids also thought
to be responsible. While both endorphins and endocannabinoids are completely
safe and natural, the former shares similarities with drugs like codeine and
heroin, and the latter is related to marijuana. While endorphins do play a
role, it turns out they may not be responsible for the feelings many people
associate with the runner's high.
A new study by researchers at the
University of Heidelberg medical school has made a strong case for
endocannabinoids. When mice were studied after running, they were found to have
elevated levels of both endorphins and endocannabinoids. They were observed to
be less sensitive to pain and less anxious after running. They were more
tranquil and spent more time in the light areas of their cage instead of
retreating to the dark corners. However, when the mice were given drugs to
block their endocannabinoid receptors, they were no longer relaxed, just as
anxious, and very sensitive to pain. Interestingly, this reversal did not
happen when opioid receptors were blocked.
While they may not be responsible for the
runner's high, according to a separate study by the University of Missouri,
natural opioids do play a part when it comes to exercise motivation. While
opioid abuse can obviously lead to lack of motivation, natural endorphin
release does provide some get-up-and-go. With many similarities between healthy
exercise and not-so-healthy drug use, both of these studies could play a role
in the development of effective drug addiction treatment programs.
According to Greg Ruegsegger, lead author
of the University of Missouri paper, "when we chemically activated their
mu-opioid receptors, those rats drastically reduced their amounts of
activity... Since exercise and addiction to substances follow this same chemical
process in the brain, it stands to reason that activating these receptors in
people with dangerous addictions could provide the same rewards they are
craving without the use of dangerous drugs or alcohol."