Personally I LOVE Pilates. I'm not really a huge exercise to get sweaty and exhausted person, so Pilates is great for me. If you do it though you have to really concentrate on pulling your stomach in (pulling your belly button to your spine). It make a huge difference on how well the ab excercises work. It also really slims your waist and hips. If you are one of the exercise to get sweaty kind of people I used to do Tae Bo and it gave me the best abs I've ever had.