We’ve all heard the term “runner’s high,” referring to the euphoric feeling one gets after a long run or intense workout. It seems obvious – pushing your body through a difficult situation and eventually getting to the finish line – that running may have an impact on your state of mind. Recently, neuroscientists have taken a closer look at this common idea and have discovered what actually happens in the brain as you run.
A 2016 brain-imaging study at the University of Arizona compared brain activity in serious runners (college distance runners) to those of well-matched (healthy, aged-matched) non-runners. For obvious reasons, the subjects could not be imaged while running, so their brains were studied at rest. In the group of runners, the research team found increased activity in regions, mainly in the front of the brain, associated with high-level executive functions and working memory. There was also an overall decrease in activity in a series of linked brain regions called the “default mode network.” The default mode network is the source of your inner monologue and also associated with mind wandering. The effects of the default mode network have been correlated with clinical depression.
So we know that at rest, runners have more activity in positive areas of the brain and less activity in potentially harmful areas, but what happens while we are actually running? The popular idea of the “endorphin rush” came from a series of studies in the 80s and 90s showing that levels of beta-endorphin increase in your bloodstream during the course of a run. Beta-endorphin targets the same receptors in the body as opiates and has some similar physiological effects. This increased level of endorphin in the brain correlates with the self-reported feelings of euphoria, or “runner’s high.” Along with the beta-endorphin increase, research has shown that the levels of circulating endocannabinoids increase after 30 minutes of running. Similarly to the chemicals found in cannabis, endocannabinoids bind to the brain’s cannabinoid receptors. Studies on lab mice have shown that these running-induced endocannabinoids are associated with reductions in anxiety and the perception of pain.
While the physical benefits of running and aerobic exercise have been well established for a while now, the mental-emotional benefits are beginning to be discovered as well. Some of these studies are still preliminary and need further investigation. It is also more than likely that factors such as genetics, gender, age, and fitness levels will affect how your brain responds to running. Even so, this research is promising and could lead to some profound breakthroughs in the difficult world of mental health. If nothing else, I hope it inspires your determination to get out for a run or do some sort of exercise more often.
Yours in Health, Dr. Alex
Project Wellness Company Madison, WI