I'm starting week 4 this weekend, and it looks like such a big step up from week 3! It goes from a total 9 minutes running in week 3, to 16 minutes in week 4. And then on top of that, the recovery walks are also much shorter in comparison with the runs than before - instead of recovering for the same length of time as the run, it's now only half that. The session is also longer overall.
How did other people find week 4? I think I'm going to be really struggling by the second half of the session, and that final five minutes must be a killer.
On the plus side, I weighed myself this morning. During week 1 I lost 2½ lbs. Week 2 I only lost ¾ lb. This week, week 3 (which is actually only since Monday as I've just changed from Monday morning weigh-ins to Friday morning weigh-ins, so there's time to even out from the weekends' excesses) I have lost 1¾ lbs. Total of 5 lbs in 3 weeks. I have plenty more to lose, so fingers crossed I can keep this up over the next few weeks.