I've just finished Week 1, and really susprised myself by being able to do it.
I started really slow, and have got a little bit faster in the running sessions (still a lot slower than anyone else, I'm sure!). The runs were exhausting, but good, and I'm enjoying them. I don't ache for days afterwards like I expected, which makes me think I'm not doing it right, but when I run I push myself as fast as I can go while still managing to run all the running portions. As I say, it's not fast, and I do get very tired because I'm not at all fit. I get a stitch about midway through the sessions, but I just keep going and eventually it goes.
I want to do week 1 again, because my aerobic fitness is appalling, and I want to build up my stamina slowly so I don't get demoralised and just give up. Has anyone else done it this way? Is this OK?