So, the runners were essentially wearing a chopped shoe Nike Air Max Classic BW Femme upper with no sole or forefoot, with lead weights attached. I do understand Nike Air Max 90 Mujer the difficulty of doing an experiment like this, but running in a sock and a shoe upper  with attached lead weights gets pretty far away from the barefoot condition, and should not be referred to as such (again, barefoot means nothing on the foot).
Rather, I think the more relevant description of what this comparison showed is that running in a “shoe” (and sock) of equivalent weight without a sole is less economical than running in a shoe with a cushioned sole – still an interesting finding. This demonstrates that presence of a shoe sole can improve economy (possibly due to cushioning effects reducing work needed to be performed by muscles, increased longitudinal stiffness, etc.). It would be interesting to compare a lightweight cushioned shoe like the Mayfly to an equal-weight, minimally cushioned shoe like a Merrell Road Glove  or Inov-8 Bare-X 180 and see how they compare (the reality is that more people are Adidas Ultra Boost Damskie running and racing in shoes like this than are running or racing truly barefoot anyway).There appears to be some amount of variation among the study subjects in barefoot/minimalist Nike Air Skylon 2 Femme running experience. One of the requirements for inclusion was running “8 km/week barefoot or in minimal running footwear (e.g. Vibram Five Fingers) for at least 3 months out of the last year.” So, the runners did not even have to have true barefoot experience. However, this study does a much better job than most previous studies in attempting to control for level of barefoot/minimalist experience when looking at unshod running (i.e., they weren’t asking a bunch of people who had only ever run in traditional trainers to run with their shoes off for the first time).I don’Nike Air Max 97 Mujer t really have a problem with this level of variation as it can be very difficult Nike Air Max 270 Mujerto recruit subjects for this type of study who meet all of the required criteria, but I am intrigued to know if there is any relationship between amount of barefoot experience and whether or not the individual was more economical when “barefoot” or in the Mayfly’s (remember, one-third of the runners had higher economy when barefoot). I’m curious as to whether individuals who run more barefoot miles (or perhaps who are more fit) demonstrate soft tissue adaptations that might improve their economy in the barefoot condition. In the press release, the authors state that “Extrapolating their data indicates that running in only slightly lighter shoes (~129 g) would offer a statistically significant 2.5% energetic advantage over running barefoot.”Extrapolating Nike Air Max 90 Femme requires following the dotted line in the above graph downward to the left, www.tomaszrozmus.pl which I don’t personally feel is statistically valid. There are no data from this region of the graph, and one cannot simply assume that the relationship will remain linear – as cushioning is reduced with decreasing shoe weight, it is entirely possible that linearity will be lost if economy is reduced. In fact, if you look at the three dark circles on the bottom line, it looks like a non-linear relationship might be a better fit for the existing points (but it’s hard to say with only three data points). One of the authors indicated to me that this region of the graph will be the subject of future study, which is fine, but extrapolating based on data provided in the present study is speculative