I love taking Bootcamp class a few times a week to get in those short bouts of high intensity interval training. Bootcamp is a good choice for that, because you get the opportunity to use all the fun toys like battle Ropes, medballs, Tires, cardiac Mtn., Echo bike and more. However I believe getting into the weight room to be able to lift heavier produces great results too, so I try and do that a few times a week as well.