You cannot expect your body to adjust instantly to a barefoot gait after spending your entire life wearing heavy shoes that drastically alter your natural gait.

You cannot expect your body to adjust instantly to a barefoot gait after spending your entire life wearing heavy shoes that drastically alter your natural gait. When I first tried running in VFF shoes I limited myself to 15 minute sessions, and even then my calves were so destroyed walking was stiff for 2-3 days. I slowly eased that limit up a few minutes at a time over the past year, and while I have a ways to go, I can run about 30-40 minutes now and my legs and feet look completely different.