I am curious to know which weeks were the hardest for those who graduated. For me, it was weeks two and seven (especially week seven run two).
My legs felt like they were number and the muscle pain lasted for two days, moving around all areas of my calf and shins. When I went for the third run that for that week, it was pretty much gone; I think it was due to lactic acid or something.
I have never had to repeat a week and there were no major issues, but those two weeks were slightly less enjoyable than the others.
I'm writing this to help other people going through the programme that they are not alone and not every run will be pleasant.