foot with an equal amount of weigh
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Labi1995
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What you’ll notice in the above graph is that all of the shod datapoints (dark circles) fall on the bottom line, whereas all of the “barefoot” data points fall on the upper line, indicating greater oxygen consumption and thus lower economy when “barefoot.” However, the stars indicate that the only significant differences werewhen the lightweight 150g shoe (Nike Mayfly, photo at top of post) was compared to a “bare” foot with an equal amount of weight attached, and when the weight-matched “bare” foot with 300g attached was compared to the shoe with 150g attached.When I read a study like this, I tend to think immediately in terms of what these results might mean from a practical standpoint to runners. What can we learn and apply from this?
Adding weight to the foot reduces economy at a rate of roughly a 1% increase in energy cost per 3.5 oz added. This means that trading your 12 oz trainers for an ultra-light flat like the sub 4 oz Mizuno Universe on race day could improve your economy quite a bit. But, presumably you’d have to also be adapted enough to run the race distance in the ultra-light flats (i.e., you should probably do some amount of training in the shoes you plan to race in so that you are used to them).The study shows that if you are already a regular barefoot or minimalist runner and are not a heel-striker (the authors specifically controlled for footstrike to avoid comparing heel striking in shoes to midfoot/forefoot when barefoot), running in a lightweight racing flat will probably not significantly change your economy (of the 12 runners, 8 were more economical in the shoe, 4 were more economical “barefoot,” and when pooled there was no significant difference economy between when the runners were shod vs. unshod). Thus, if you feel that lightweight shoes are desirable in a race situation, go for it – they might even improve your economy a bit.Both of these findings are interesting and of practical value, and the study raises a ton of questions that will likely be examined in future research. Running Times went so far as to run a headline saying “Here’s Proof Barefoot Isn’t Better” – well, barefoot was in fact better for one-third of the subjects, but we don’t really know why. Given the tendency to jump to interpretations like this, it’s important to recognize that like ] every scientific study, there are some limitations that should be mentioned related to the interpretation of the results – below are some things to think about:None of the study subjects were actually barefoot, which is why I have been using quotation marks whenever I refer to the “barefoot” condition. In the study Methods section it mentions that “For the duration of the experiment, subjects wore very thin, slip-resistant yoga socks for safety and hygienic purposes.”Would this have any effect on the results? I don’t really have any idea (what do you barefoot runners think?). Certainly, wearing a sock does add a layer of material between the foot and the ground that could alter sensory perception and plantar abrasion/shear (reducing the latter could actually improve economy relative to barefoot when running on a treadmill – truly barefoot treadmill running can create friction with the belt and resulting discomfort for some people). Just as people get sensitive when the phrase “barefoot-shoes” gets thrown around, I think it’s important to be clear with terminology – barefoot means nothing on the foot. For similar reasons to the above, it’s debatable whether adding weight to the bare foot tells us anything of practical relevance about barefoot running. Here is the description of how weight was added to the “bare” foot:
“To add mass to each foot during barefoot trials, we modified the uppers of a different model of running shoes to allow for easy attachment of small lead strips while still simulating barefoot running (Figure 3). We removed the outsole, midsole, and the entire front portion of the shoe upper, anterior to the mid-shaft of the fifth metatarsal, leaving only the heel counter, thin fabric arch section, tongue and laces.”
Adding weight to the foot reduces economy at a rate of roughly a 1% increase in energy cost per 3.5 oz added. This means that trading your 12 oz trainers for an ultra-light flat like the sub 4 oz Mizuno Universe on race day could improve your economy quite a bit. But, presumably you’d have to also be adapted enough to run the race distance in the ultra-light flats (i.e., you should probably do some amount of training in the shoes you plan to race in so that you are used to them).The study shows that if you are already a regular barefoot or minimalist runner and are not a heel-striker (the authors specifically controlled for footstrike to avoid comparing heel striking in shoes to midfoot/forefoot when barefoot), running in a lightweight racing flat will probably not significantly change your economy (of the 12 runners, 8 were more economical in the shoe, 4 were more economical “barefoot,” and when pooled there was no significant difference economy between when the runners were shod vs. unshod). Thus, if you feel that lightweight shoes are desirable in a race situation, go for it – they might even improve your economy a bit.Both of these findings are interesting and of practical value, and the study raises a ton of questions that will likely be examined in future research. Running Times went so far as to run a headline saying “Here’s Proof Barefoot Isn’t Better” – well, barefoot was in fact better for one-third of the subjects, but we don’t really know why. Given the tendency to jump to interpretations like this, it’s important to recognize that like ] every scientific study, there are some limitations that should be mentioned related to the interpretation of the results – below are some things to think about:None of the study subjects were actually barefoot, which is why I have been using quotation marks whenever I refer to the “barefoot” condition. In the study Methods section it mentions that “For the duration of the experiment, subjects wore very thin, slip-resistant yoga socks for safety and hygienic purposes.”Would this have any effect on the results? I don’t really have any idea (what do you barefoot runners think?). Certainly, wearing a sock does add a layer of material between the foot and the ground that could alter sensory perception and plantar abrasion/shear (reducing the latter could actually improve economy relative to barefoot when running on a treadmill – truly barefoot treadmill running can create friction with the belt and resulting discomfort for some people). Just as people get sensitive when the phrase “barefoot-shoes” gets thrown around, I think it’s important to be clear with terminology – barefoot means nothing on the foot. For similar reasons to the above, it’s debatable whether adding weight to the bare foot tells us anything of practical relevance about barefoot running. Here is the description of how weight was added to the “bare” foot:
“To add mass to each foot during barefoot trials, we modified the uppers of a different model of running shoes to allow for easy attachment of small lead strips while still simulating barefoot running (Figure 3). We removed the outsole, midsole, and the entire front portion of the shoe upper, anterior to the mid-shaft of the fifth metatarsal, leaving only the heel counter, thin fabric arch section, tongue and laces.”
