Last week I couldn't believe I'd manage the step up to 3 minute runs without really noticing. 2 stone overweight but I do cycle to work (about 6 miles), so perhaps that already prepared me!
When Sanjeev said "I know it's tiring but keep going to the end" I'm thinking - "no, it's not really!" I've got past the stage of saying "Thank God" when it says time to slow down, to thinking "I could actually go on a bit further". However, I stuck to the regime.
Whether I'll hit a brick wall in the coming weeks I don't know but at the moment I'm really glad I'm doing this!