I did the same thing when I first got Vibrams - ran about 4 miles with no prior barefoot running. Felt great during, then I could barely walk the next couple d

I did the same thing when I first got Vibrams - ran about 4 miles with no prior barefoot running. Felt great during, then I could barely walk the next couple days (my calves were totally dead...). A year later, I'm still running with them, though mainly for my shorter runs. They've helped develop leg muscles I didn't know I had, which I think is helping keep my knee injury at bay. Highly recommended.