For the past 2.5 weeks, I had not been great about getting to the gym - no more than 2 times per week. So, I just kept doing W3. Today I figured I needed to bump it up to W4 and boy was it hard! Those two five minute intervals, with less recovery time, are brutal! I got through it, though, and I feel great now - but I am not eager to go back and do it again tomorrow! (I know it's best to take a break between days, but my only days I can get to the gym are Tue, Wed, Fri and Sat).
Anyone else on W4 now?