For this workout, you can use either an aerobics step or simply a set of stairs in your house. Step work is important because you exercise lots of leg muscles—burning tons of calories along the way and adding muscle tone and definition to your thighs and glutes. As well, these moves are designed to really get your heart rate going.
To maximize this workout, do as many of each of these exercises as you can, as fast as you can. You can modify the workout to your own fitness level by going with the less-demanding Easier Options—which are lower impact—until you have built up your aerobic stamina (but try to do at least one 180-Degree Squat Thrust!). If you are doing the Easier Option moves, build intensity by doing more repetitions of them each time until you can do the tougher move for the complete time allotted.