The only issue I've had thus far has been some tightness in my calves. I always had tight calves but that article points out how when running barefoot, your calves hold up the heel to keep it from striking too hard and I will attest that you definitely feel this. I definitely am running more efficiently since I started in the Chucks.
Same thing happened to me when I was unemployed. I was working out almost everyday and it was the only thing that kept me sane. mahalo
~Chach~

