30 day shred IS a tough work out. Bootcamp style, I would guess. I went from Denise Austin's dvd's and tv show to her and I thought I was going to die!!! I since started taking kung fu and it was much harder and even still when I put in the shred dvd, it is still hard but doable.
To sum up, it is hard, but VERY effective and so darn brief that b4 you know it you are done.
Good luck everyone.