The “runner’s high” is a term used
confidently and frequently in the running community. I remember an athlete in
my Gen Chem class enquiring if we could learn which chemicals are released
during the runner’s high, and when I asked some endurance athletes on campus if
they’ve ever experienced the phenomenon the response was an overwhelming “Of
course!” usually followed by a, “Well, at least, I think I have.” Sophomore triathlete Sarah Backer has competed in so
many endurance events, including a Half-Iron Man, that she’s lost count. She
tells me that the feeling she considers to be a runner’s high is much different
than the usual feeling of calmness and heightened life-appreciation she gets during
a daily workout. “After a long endurance event, it’s overload; it lasts longer,
is more profound, and more intense,” she said. Others I spoke to claimed that
they usually feel at peace with the world after working out, but wouldn’t
necessarily compare it to a high. Still others claim they get little enjoyment
out of a workout, and simply feel sick during or after a long run. So, is the
runner’s high real? And if it is, how come some people seem to miss out? Recent
research suggests two explanations for the high: endogenous opioids and
endogenous cannabinoids.
Endogenous Opioid Explanation:
Opioids include the addictive drugs
morphine and opium, but the body also produces its own natural or “endogenous”
opioids, such as endorphins. Researchers in Germany monitored the release of
these endogenous opioids in trained athletes during and after a two-hour run,
and asked the runners to complete a survey about their current happiness level.
The happiness ratings increased significantly after exercise, and the ratings
were inversely correlated with opioid binding. Specifically, running affected
the opioid binding in the prefrontal cortex and limbic areas, which are
associated with personal affect and mood. Researchers in Brazil tested similar
theories on rats trained in resistance training, and brain scans revealed very
similar patterns in the rats’ opioid receptors.
Endogenous Cannabinoid Explanation:
Less literature is available about
the possibility of endogenous cannabinoids—the body’s chemicals that bind to
the same receptors as marijuana—as a source of an endurance-induced high. One
study published in Neuroreport in
2003, however, examined cannabinoid release in the brains of male college
runners. The research was the first to present evidence that exercise of
moderate intensity activates the cannabinoid system.
How come I’m missing out?
Still,
some researchers and runner’s high skeptics remain unconvinced. If these
chemicals are released during exercise, how come they aren’t released in all
people, every time they exercise? Why does no clear consensus exist among
athletes about what the high feels like, and why don’t more athletes become
addicted to the rush? One hypothesis
states that humans simply expect to feel good after completing a difficult goal.
Since we expect to feel content, proud, and joyous after a major accomplishment,
good feelings ensue in a placebo-effect fashion. Others resort to a Darwinian
explanation. In our ancient past, humans could outrun animals in a hunt not by
speed or agility, but by endurance. Humans had to be able to out-run animals,
and, in order to do so, the human brain had to produce some incentive. This
incentive took the form of exceptional euphoria after an intense endurance
event, and the reward pathway persists in some individuals today. There is not
much scientific research being conducted about these hypotheses, so the issue
is still up for debate. Maybe the feelings are symptoms of complete exhaustion,
and athletes who experience them are simply going a little nuts.
It
is clear that there is still a wide opening for more conclusive research on the
feelings that so many athletes crave, but it is also certain that if incredible
exercise-induced feelings were not real, endurance athletes would not exist. After
all, runners can’t all be crazy enough to choose to put their bodies through
misery without some sort of mental pay off.
And
with that being said, I’m off to chase that runner’s high. Maybe I’ll see you
on the bike path.
This article was previously published in The Catalyst, a publication of the Colorado College in the 2011-2012 school year
