I am on W4 due to run R2 today. Upon the advice of many of my friends and specifically my brother who competes in loads of triathlons, I wanted to try barefoot running. As there is a considerable risk of injury if you don't start out very gradually, I decided to use the C25K plan to help me along my way. (It is worth noting I couldn't have run 5k with heel strike form though even if my very life depended on it!) Anyway, I have bought a pair of Brooks PureDrift and absolutely loved every step of running I've done in them. Weeks 1-w4r1 were surprisingly doable. Just the right amount of challenging. I did have some foot soreness at times but nothing major and it went away quickly. It felt like the tiny muscles in my feet were getting a work out and were sore after but would recover after 24/48 hours. I had no soreness in my legs though. However, w4r1, though I felt good as I ran it, has left my calves in tatters. Should I run again today even though they are very sore? I'm afraid I'll break form and start heel striking - which I just can't do because of the PureDrift shoes. They are very minimalistic and not designed for heel strike running. Up until this point leaving a day's rest was plenty of time to recover but the jump between w3 and w4 plus the doing barefoot running form is introducing me to more soreness than I was experiencing before. I don't want to injure myself and I love the challenge and feel of barefoot running style. Not giving that up - maybe I should take it even more slowly? Or should I just run through the pain? Assuming I even can and don't have muscle failure in my calves and start heel striking? I'm open for ideas and advice!