Beware Evolutionary Storytelling: The Case of Barefoot Running
Some of the glow has come off trendy barefoot-style running as newer evidence suggests that it may not be as natural or beneficial, in terms of avoiding injury, as some thought. As I thought too: I was briefly very into it but sustained an injury as a result that's still with me and have since gone back to running shoes.
The craze was based on an evolutionary story about how our ancient ancestors ran long distances on the savannah in a strategy to tire out animals they were hunting, striking the ground toward the front of the foot, as the barefoot style seems to demand. See Tom Hartsfield's fine summary and analysis at RealClearScience.
Well, a study in PLoS One has complicated the tale ("Variation in Foot Strike Patterns during Running among Habitually Barefoot Populations"). When researchers looked at a broader selection of those outstanding African runners who gave the world the idea, who go barefoot in their daily life including when they run, it turned out that some indeed run on the forefoot -- but they tend to be running shorter distances at high speed. What about Africans who run in a way closer to what a long-distance runner in our part of the world does? They strike the ground sometimes with their full foot and sometimes with the heel:
Our data support the hypothesis that a forefoot strike reduces the magnitude of impact loading, but the majority of subjects instead used a rearfoot strike at endurance running speeds. Their percentages of midfoot and forefoot strikes increased significantly with speed. These results indicate that not all habitually barefoot people prefer running with a forefoot strike, and suggest that other factors such as running speed, training level, substrate mechanical properties, running distance, and running frequency, influence the selection of foot strike patterns.For heel-striking, shoes would seem to be the preferred option.
In brief: Running in the barefoot style works well for those for whom it works well. For other, perhaps not. It depends on the runner and the parameters of his run. The lesson seems to be that the fact you can tell a charming story about the distant past is no basis to assume you actually know what happened in that long-ago time. Nor is it a basis for choosing a running shoe.
Image: FiveFinger Running Shoes, danbruell/Flickr.