MINNEAPOLIS (WCCO) -- This coming Monday, you might see a few of your co-workers limping around the office after almost 12,000 people lace up for this Sunday's Twin Cities Marathon -- 26.2 miles that circle around Minneapolis and St. Paul.
As one marathoner who's competed in the past put it, "My muscles, my legs, my calves … felt like crap."
So, is running 26.2 miles bad for our health?
"Generally speaking, no," said Dr. Paul Mellick, a professor of exercise science at the University of St. Thomas. "Usually you get damage, you have muscle damage which is a perfectly natural part of exercise adaptation."
It's often hard to convince people of the health benefits after hearing the origin of the name marathon. According to ancient Greek legend, a courier named Pheidippides ran 25 miles to announce a victory at the city of Marathon.
Immediately afterwards, he collapsed and died.
"Maybe 26 miles is a little too much for some people," said Essence Stiggers of St. Paul.
Studies have shown elevated levels of troponin, a muscle protein that can rupture when the muscle is damaged, are in a runner's blood right after a marathon. But generally, there's no structural damage to the heart.
"It's short-term, the body can adapt to it," Mellick said. "It's borderline healthy damage."
Mellick says this is how exercise is supposed to work -- you break down the muscles and the body adapts. Weight training, for example, causes minor damage to muscles. Then, the muscles heal over 24 to 48 hours and come back stronger.
But, he says it's important to train for a marathon so a runner's body can adapt to the stress of exercising for so long.
"If your body isn't used to that, not trained to do that, it's putting too much a load on your heart," Mellick said.
He points out other possible side effects of a marathon, like hyperthermia, hypothermia and water intoxication, all of which are preventable.
As for structural injuries to muscles, bones and joints, Mellick says it's not a big problem if you're running a marathon every so often.
"If you're running 20 miles a day, you're going to see some overuse issues," he said.
Dr. Mellick stresses that no one should attempt running a marathon without training.
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