These longer runs, uninterrupted by walking are great. It's interesting that the first few weeks of the program I was focused on the breaks not the running (always looking at how much running I wouldn't be doing as my motivation!) But now it's all about the running and learning to pace myself.
also, I can really feel how much fitter I have become now. I'm 55 and have a 4 year old son and it's great to be able to move better when playing with him, kicking a football, playing tag, or even just carrying him when he's asleep.