The Runner's High

I saw an interesting story in the New York Times today about research into the mythical runner's high.

I'll post some excerpts:

The runner’s-high hypothesis proposed that there were real biochemical effects of exercise on the brain. Chemicals were released that could change an athlete’s mood, and those chemicals were endorphins, the brain’s naturally occurring opiates. Running was not the only way to get the feeling; it could also occur with most intense or endurance exercise.

The problem with the hypothesis was that it was not feasible to do a spinal tap before and after someone exercised to look for a flood of endorphins in the brain. Researchers could detect endorphins in people’s blood after a run, but those endorphins were part of the body’s stress response and could not travel from the blood to the brain. They were not responsible for elevating one’s mood. So for more than 30 years, the runner’s high remained an unproved hypothesis.

But now medical technology has caught up with exercise lore. Researchers in Germany, using advances in neuroscience, report in the current issue of the journal Cerebral Cortex that the folk belief is true: Running does elicit a flood of endorphins in the brain. The endorphins are associated with mood changes, and the more endorphins a runner’s body pumps out, the greater the effect.....

For athletes and nonathletes alike, the results are opening a new chapter in exercise science. They show that it is possible to define and measure the runner’s high and that it should be possible to figure out what brings it on. They even offer hope for those who do not enjoy exercise but do it anyway. These exercisers might learn techniques to elicit a feeling that makes working out positively addictive.

The lead researcher for the new study, Dr. Henning Boecker of the University of Bonn, said he got the idea of testing the endorphin hypothesis when he realized that methods he and others were using to study pain were directly applicable.

The idea was to use PET scans combined with recently available chemicals that reveal endorphins in the brain, to compare runners’ brains before and after a long run. If the scans showed that endorphins were being produced and were attaching themselves to areas of the brain involved with mood, that would be direct evidence for the endorphin hypothesis. And if the runners, who were not told what the study was looking for, also reported mood changes whose intensity correlated with the amount of endorphins produced, that would be another clincher for the argument.

Dr. Boecker and colleagues recruited 10 distance runners and told them they were studying opioid receptors in the brain. But the runners did not realize that the investigators were studying the release of endorphins and the runner’s high. The athletes had a PET scan before and after a two-hour run. They also took a standard psychological test that indicated their mood before and after running.

The data showed that, indeed, endorphins were produced during running and were attaching themselves to areas of the brain associated with emotions, in particular the limbic and prefrontal areas.

The limbic and prefrontal areas, Dr. Boecker said, are activated when people are involved in romantic love affairs or, he said, “when you hear music that gives you a chill of euphoria, like Rachmaninoff’s Piano Concerto No. 3.” The greater the euphoria the runners reported, the more endorphins in their brain.

“Some people have these really extreme experiences with very long or intensive training,” said Dr. Boecker, a casual runner and cyclist, who said he feels completely relaxed and his head is clearer after a run.

That was also what happened to the study subjects, he said: “You could really see the difference after two hours of running. You could see it in their faces.”

In a follow-up study, Dr. Boecker is investigating if running affects pain perception. “There are studies that showed enhanced pain tolerance in runners,” he said. “You have to give higher pain stimuli before they say, ‘O.K., this hurts.’ ”

And, he said, there are stories of runners who had stress fractures, even heart attacks, and kept on running.