Topics in science are like buses. You wait what seems forever for a certain topic to arrive, and when it does there are three at once. Or something like that. Basically, whenever something new hits a science journal it seems like it snowballs across many journals. We have seen this very recently with hypoxia research which I have already mentioned and will come back to in a future article, and with vitamin D discussion, which I plan to cover very soon. It looks like we are also seeing it with discussion of barefoot exercise. A previous article I wrote discussed the way that training shoes have altered our “natural” running technique in that we now make impact with the ground with our heels. This is painful when barefoot, so no shoes typically makes you run on your forefoot.
But what about walking? Research coming out of the University of Utah has given a reason why we walk heel-first: energy conservation. This information, published in the latest issue of the Journal of Experimental Biology, involved getting human subjects to walk in three different manners: the “normal”, which is heel-first; “toe-first”, in which the heel is slightly raised in order to prevent it from contacting the floor; and finally on “tip-toes”. The difference in energy requirements was quite drastic, with “toe-first” using 53% more energy, and “tip-toes” using a massive 83% more! What I find truly interesting is that when comparing these as running styles there was no difference between runners’ energy efficiencies when comparing flat-foot versus forefoot running. I guess this is another victory for the idea of “natural” forefoot running.
Source: Cunningham CB, Schilling N, Anders C, Carrier DR. The influence of foot posture on the cost of transport in humans. J Exp Biol. 2010 Mar;213(Pt 5):790-7.