I have been doing this with a group for 60 days. We decided after the first week that we would scale back and do it 3 days a week, MWF. I have lost roughly 20 lbs during this period. If you can push through the first week/ 10 days it will get "easier", although the 2nd set of workouts push the 55 minute mark. I like the fact that there is no extra equipment to buy. One of the guys that is working out with us, did the P90x and said Insanity is tougher and its not close. If you are looking to burn fat and get into shape quickly, this will do it!