If you don't buy anything else this year, buy this DVD!I have never bought a workout video before and was sceptical but decided there must be an easier way than going to the gym every day. After reading all of the reviews I plumped for this one, based on the concept of interval training and the very few bad reviews.The DVD is made up of 4 sections - cardio, box, tone and belly blitz. Each section is about 20 minutes long and promises to burn up to 500 calories at a time and continue to burn fat for 48 hours. As it's based on interval training, only 20 minutes of these workouts equates to over an hour or normal aerobic exercise such as jogging. I wouldn't advise someone who is comletely unfit to start with this DVD as it is tough going and works you very hard. I have a wii fit and unlike the wii, this really gets your heart rate going. At times I found myself incredibly out of breath (which is good of course!!) and struggling with some of the moves. I started this DVD last Thursday (it's now Monday) and have already noticed a considerable difference - I have been eating 'sensibly' - normal meals but no chocolate/crisps in the week... and I am certainly not on a strict diet.The sections are enjoyable - particularly the cardio and box ones and the belly blitz works your abs brilliantly. I have found myself aching for days after, and using muscles that I didn't even know I had. The beauty of this DVD, aside from being able to do it in the comfort of your own home, is that you don't feel guilty for just doing a 20 minute section because you work so hard for those 20 minutes.I'm not going to lie - it's not easy, and there is no point buying it if you are not determined because it's very hard work. I agree with other reviews, that Hannah Waterman is a bit cocky which can be annoying but there are 2 male trainers with her who are the main instructers so you don't actually have to listen to her!Overall, I'd say it's well worth the money, and I'm incredibly pleased that I am seeing results already BUT you must be willing to stay committed (no good if you turn the DVD as soon as it starts to hurt!) and be prepared for some horrendous workouts, aching muscles and lots of sweat!!!