Just thought I would share my experience!
I am on week 7 - the 25 minutes.....last week I used a treadmill for the first time ever. It was the 25 minuter at the end of week 6 - and I found it really easy on the treadmill compared with running outside.
I also found it very difficult to work out how fast I was going compared with my usual pace (I suppose I couldn't see how fast the scenery was passing!). Just thinking...if I found it easier it may be worth anyone training on a treadmill to go outside also...otherwise you may be in for a shock on your first 5k or park run!
Anyway, happy shuffling