Runner's High
Runner's World magazine, 6/2004 edition
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Kolata notes that running and runner's high seem linked more by chronological association than by scientific proof. Endorphins, some of the body's natural painkillers, were discovered in 1975. Running took off a few years later. Soon, legions of runners were bumping into each other at weddings and cocktail parties, saying things like: "Who needs drugs? I get an endorphin rush every time I run more than 10 miles."
Of course, talk is cheap. Science demands rigorous proof. And last year, in her book and a Times article, Kolata pretty much buried runner's high forever. She interviewed a number of leading experts, and none of them bought into the runner's high theory. "
I believe this endorphin in runners is a total fantasy in the pop culture," said psychobiologist Huda Akil, Ph.D., from the University of Michigan.
The endorphin theory had several problems, the most serious being that endorphins are too large to pass through the blood-brain barrier that border-patrols your gray matter. And if something can't get into your brain, it can't make you high. Too bad. What are we going to talk about at cocktail parties? Turns out the answer could be that 1960s favorite: marijuana.
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Since the body is an intelligent system that doesn't develop receptors for no reason at all, this meant the new receptor must be home to a natural body chemical--and not just THC, an exogenous, or "outside the body" substance. The natural chemical was discovered in 1992. It's called anandamide, from the Sanskrit word for "bliss." Anandamide is very similar to THC, and it produces pleasant feelings of relaxation and pain cessation similar to those often described by runners and pot smokers.
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He started by devising a simple experiment with a small group of subjects who ran or bicycled for 40 minutes at 76 percent of their max heart rate, and then had blood samples drawn immediately after exercising. Next the blood samples were flown to a special lab in Irvine, California. The results showed that both the runners and bicyclists had significantly more anandamide in their blood after exercising, with the greatest increase among the runners.
Equally important, as Dietrich already knew, anandamide doesn't have a blood-brain barrier problem, the way endorphins do. If you've got anandamide in your blood, it's going to reach your brain, where the cannabinoid receptor will hungrily grab it and give you a nice buzz. "Anandamide is a tiny little fatty acid that crosses the blood-brain barrier like nobody's business," says Dietrich.
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So a runner's high doesn't come from endorphins. It comes from a blissful substance that Dietrich believes could help people suffering from chronic pain.
