Running can cause injuries.
Photo: © 2009 Jupiterimages Corporation
At no point since the Greek messenger Pheidippides ran just over 26 miles from the city of Marathon back to Athens to announce a military victory—and dropped dead at the end—has this grueling endurance test been more popular.

According to The New York Times, in 2008 approximately 205,000 people entered the five most prestigious marathons in Berlin, Boston, Chicago, New York and London. And there are thousands more runners who compete in hundreds of other marathons around the world.

No matter whether they are training to go 26.2 miles or just jogging a few miles every week for exercise, runners put their bodies at risk of injury, particularly if they aren't in great shape to begin with. According to Dr. Kathleen Weber, director of primary care sports medicine and women's sports medicine at Rush University Medical Center in Chicago, some of the most common running injuries are "overuse injuries" to knees ligaments, Achilles tendons and calf muscles.

While Dr. Weber, who is a veteran of several marathons, says the classic figure of a runner is someone who is slender without much body mass, but that doesn't mean people with other body types are at greater risk for injuries. "There are clearly individuals who don't fit into that category who are good runners, who are able to tolerate the pounding," she says. "They tend to be mechanically efficient in their running ability."

One common reason runners get injured is that they don't allow their bodies enough time to recover between workouts. Many runners, particularly those preparing for their first marathons, use logs suggested by event organizers to set their training schedule. "You're supposed to run this much on this day and this much on that day. They follow it to a tee because they feel that if they don't, they're not going to be successful in finishing the marathon," Dr. Weber says. "Even when they're feeling sore or a muscle hurts or they're feeling tired, instead of taking the day off and saying, 'My body needs a break,' they go ahead and push through. They injure themselves because they're really not listening to what their body is telling them."

Dr. Weber says she routinely tells patients to mix in a day or two without a run every week, even during training periods. How do you know if that sore feeling is actually a result of overtraining and you need a break? Some of the subtle hints include an elevated resting heart rate, aches and pains and feeling more tired and irritable than normal, she says.