Holy Crap!! Week 4 is going to be a tough one. I don't think I agree with the jump in running time. In week 3, I ran for 9 minutes total. In Week 4, I'm expected to run for 16 minutes. That's a 77% increase!! I definitely felt the difference. When I woke up on Monday morning, the feet hurt, mostly, and really the whole body hurt. We'll see.