Runner's high and your heart

They're talking about it again — that mythical point when you're exercising hard and your mind and body seem to separate and this euphoric feeling comes over you. Runner's high, some folks call it. Hooey, according to others.

Meriam Webster defines it as "a feeling of euphoria that is experienced by some individuals engaged in strenuous running and that is held to be associated with the release of endorphins by the brain."

Last week, researchers at the University of Iowa rekindled the debate with their innocuous-sounding paper Exercise Enhances Myocardial Ischemic Tolerance via an Opioid Receptor-Dependent Mechanism.

In English, that means "runner's high" may not only make you feel good, it may help ward off heart attacks.

The study, published in the American Journal of Physiology's Heart and Circulatory Physiology, found that rats didn't reap the cardiovascular benefits of vigorous exercise when researchers blocked the receptors that bind morphine, endorphins and other opioids. The study's authors say their research is the first to link the production of those chemicals during exercise to the "cardio-protective effects of exercise."

Almost three years ago, a study out of the Georgia Institute of Technology found that runner's high is caused by anandamide, a member of the family of chemicals known as cannabinoids.

Andanamide produces effects similar to THC, the active ingredient in marijuana, the study said. The body produces it as a response to stress, which helps the body control the pain associated with the stress. The lead researcher, Arne Dietrich, has run several marathons and has recorded a personal best of two hours and 52 minutes, which qualifies him as someone who has certainly felt some pain.

Dietrich's study caught a lot of attention in magazines like this one and some blogs.

Dietrich didn't investigate whether the THC-like high that some runners may experience actually makes the heart stronger, but he was convinced it did no harm.

For me, that runner's high usually comes around the 36-kilometre point of a marathon, just before I can swear that I see this staircase rising up from just around the next corner. As I approach, it's clear that it leads to a doorway somewhere up in the clouds. The door opens slowly and a bright light lures me up the stairs.

I take another bite of my brownie — er, energy bar — and crank up the Led Zeppelin.