I have the insanity work out. it will make you cry. Every time I did one of the work outs I tweaked my back. This is just explosive movements and lots I MEAN LOTS of cardio. I was doing a boot camp for about 4 weeks before doing this, HIIT. it is hard I'm sure it would work but i will tell you this.....I will wait until I reach under 140 and have had some more weight training and endurance under my belt before I even attempt the videos again. it's not that i was sore ( I was) but the fact that Someone actually thought about producing something like this to sell to the general public, that's what was insane. I bet you he has made a mint off of these things. i would wait or try ebay I'm sure you will find them on there way cheaper. trust me people probably wanted to sell these after completing 3 dvds.
okay stepping off my soap box.