This video is truely an 'EXTREME CARDIO' killer!!! Really, I was sweating so hard that I had to stop and take a rest after doing the 180's...... I thought that I was going to have a heart attack =).... I did turn it back on after having a 5 minute break and completed the entire video, but it was EXTREME!!! This will get you in shape and I really don't think anyone really could complain about getting enough cardio from this DVD~*** This was much harder than the 30 day Shred because it integrates much more cardio. I bought this along with 'No more Trouble Zones' and I really like the combination. I did the 'No more Trouble Zones' DVD first, and it really was not that hard for me (it is much more strength focused rather than cardio), but the next day I was sore everywhere!!!! I exercise all the time, so this was a good change and challenge to my routine!!! 'No more trouble Zones' will hit all the muscle groups, (especially your arms and you will feel such a 'good sore feeling' the next day), and 'Boost Your Metabolism' will give you a crazy killer cardio workout. I have to admit, I love to rotate these 2 videos everyother day, but I take one day just to rest, and one day to run on a treadmill to recover. I would say that these videos are really good if you want a step up from the Shred. There are new excercises that hit muscle groups that I never thought existed. (I use 5lb weights) The only thing that I noticed which hindered me from initially purchasing the new DVD where the 'titles' of the DVD's. They did not seem very catchy...the '30 day Shred' title was a very catchy title..... I thought that they actaully were older videos from the 90's.... I hope her marketers read this, beacause I think one or 2 word titles are more catchy...these did not catch my attention, but none-the-less buy these-----> they are GREAT videos....like Jillian says ...."They won't dissapoint"!!!