When it comes to running shoes, softer isn’t necessarily better.
That’s the word from Luxembourg, where researchers at the Sports Medicine Research Laboratory have found that shoes with cushioned midsoles are no better at preventing injury than those lacking extra padding.
As Runner’s World reports, the team followed 215 runners—most of whom cover about six miles twice a week at a 10-minute pace—over the course of five months.
Researchers assumed they’d see more injuries among those whose landings were cushioned by the less padded shoes, because the “shock-absorbing qualities of a running shoe are put forward as being especially important, since they influence repetitive impact forces that could be responsible for microtrauma and overuse injuries,” as their paper states.
But that wasn’t the case. Even heavier runners—those whom logic suggests would need the cushioning most—didn’t seem to benefit from the softer soles.
If sole softness didn’t predict injury, what did? According to the study, those runners with prior injuries were most likely to get hurt during the trial period. Those with higher BMI who seemed to exert themselves more also suffered more injuries, though as Runner’s World points out, “injury incidence in the high-BMI group was the same for both types of midsoles.”
Experience and participation in other sports, meanwhile, seemed to lessen one’s chances of injury.
Coming on the heels—pun very much intended—of last month’s discovery of a fourth type of footstrike, this latest study underscores how tough a challenge shoemakers face. Perhaps synthetic-tissue biologists will have better luck.