It's AWESOME! I won't be measuring until this weekend, but I know I'm already getting results. I did it Sunday, Monday, skipped Tuesday, and did it yesterday, and will do it tonight. I'm not nearly as sore now as I was, and I am finding my endurance is much better (with yesterdays workout). I would have never thought I could get so much out of 20 minutes. The cardio segments are very effective, and 2 minutes seems like forever But then you move right into the strength circuit and can feel your muscles burning. I'm going to keep going with it for the full 30 days, but I will probably continue to take one day a week off and just do cardio on that day. I have been doing either a walk, Turbo Jam 20 or Tae-Bo in the mornings, and the Shred in the evenings.