I did this run this morning with a friend and found it alot easier than I had anticipated. I was actually able to have a conversation when running and I was gaining speed with each 5m section. I think the secret was that I wasn't thinking about the run and just did it. Feeling like I have found my groove this week. Much of this I think may be having read some of the post on here and understanding how each run builds to the next, ie 3x5 min runs totalling to 15mins and building to 2x8 min runs totalling 16 mins and building to a single 20min run. Not the big jumps you think you see when just reading the next run sequence.
I haven't run since I was at school and that was reluctantly and involved a bus ride for part of the cross country circuit. I am somewhat in a state of disbelief that I am doing this and enjoying it. Who would of thought!!