Wow quick responses, thanks guys.
I have done 2 x 20 milers, the first one I did on week 7, I ran 18 miles at a good pace - 2:08 then jogged the last 2 miles slowly at 8 min/mile pace = 2:24. Week 8 - 10m, week 9 - my 1:20:20 half marathon, week 10 - 20 miles EASY in 2:30 felt very comfortable. I am on week 11 of 13...(only 13 week designated plan but was training before that at around 20-25 miles per week then anyway). Did 18 miles on week 3 in 1:59:30...On my last 20 miler (week 10) I felt tired starting off but was running at comortable pace, started aching around my IT band area around mile 17...
Feedback appreciated, thanks...