Before competing in a marathon, it's smart to build up your endurance with weekly runs or one practice marathon the night before. Be prepared with this Groupon.
- $25 for an Endurance Sports Program registration ($100 value)
The Runner's High: A Dose of Happiness, One 5K at a Time
Once dismissed as myth, the euphoria some experience after a run or an intense workout is rooted in our brain chemistry—read on to learn more.
The runner's high is that elusive burst of euphoria that can transform a grueling marathon into a walk through the clouds. Many athletes claim to feel it every time they exercise, whereas others insist it's only a once-in-a-lifetime experience. Since the 1970s, conventional wisdom has held that the feeling is the result of a rush of neurochemicals called endorphins. Since endorphins attach themselves to receptors in the brain associated with pain relief, runners felt a high similar to that of morphine, only without a nurse having to keep up while wheeling an IV cart close behind.
For years, though, scientists doubted endorphins' role. The chemicals may have shown up in a runner's blood after exercise, but the molecules were too large to pass through the barrier between the cardiovascular system and the brain, making any effect on pain receptors unlikely. In 2008, however, German researchers used newly developed chemicals to detect the presence of endorphins in the brain with a PET scan—trumping the previous method of an invasive spinal tap. Comparing brain images taken before and after a two-hour run, the Germans showed not only that endorphins were present, but that they attached themselves to parts of the brain associated with emotions. The runner's high wasn't a shot of morphine—it was literally a love of running.
Still, more recent studies have altered even that theory. It now seems likely that the high results from a cocktail of multiple neurochemicals, each of which moves along its own neural pathway. One possible culprit is anandamide, part of a class of chemicals called endocannabinoids. A 2012 study found that anandamide showed up in the bloodstream of both humans and dogs after exercise, suggesting it may have played an evolutionary role in developing humans' distance-running and frisbee-chewing abilities.