Why do 90 percent of Runners miss training time every year due to injury

Gretchen Reynolds, writing about running for The New York Times, claims that studies estimate that “90 percent of runners miss training time every year due to injury.” What causes the injuries? To answer that question researchers have examined and then blamed an assortment of causes from running longer distances, being too heavy, over-striding, wearing the wrong running shoes, wearing no shoes and going barefoot, weak hips, following a wrong diet, and rough pavement to run on. Researchers at Harvard Medical School, to get more reliable answers to the runners’ injury question, decided to examine the history of a group of long time runners who have never experienced an injury. What were they doing that kept them from never getting hurt? The study was published in December in the British Journal of Sports Medicine. The researchers recruited 249 experienced female recreational runners. They had one thing in common—they all struck the ground with their heels when they ran. Most runners are heel strikers and, according to Reynolds, heel striking is believed by many running experts to cause higher impacts than landing near the middle or front of the foot. The study focused on young women so researchers would not have to control for gender in the results. The researchers tracked the runners for two years. During that time, according to Reynolds, more than 100 of the runners sustained an injury that was serious enough to require medical attention. Another 40 reported minor injuries, while the rest remained uninjured. Twenty-one of the runners not only did not become injured during the two-year study but they also had not ever had a prior running injury. The scientists compared that small group’s impact loading with the pounding experienced by the seriously injured runners. They found that the never-injured runners, as a group, landed far more lightly than those who had been seriously hurt. This was true even when they controlled for running mileage, body weight and other variables. Reynolds noted that “the finding refutes the widely held belief that a runner cannot land lightly on her heels.” Irene Davis, Ph.D., a Harvard professor who led the study, said, “One of the runners we studied, a woman who has run multiple marathons and never been hurt, had some of the lowest rates of loading that we’ve ever seen.”

posted Saturday July 21st