This step workout is broken into three segments for different levels of stamina and complexity. You can do just level 1 (12 minutes) or continue through level 2, for 22 minutes, or through level 3, for 32 minutes. Within each segment, Keli Roberts's assistants demonstrate different intensities, so you can work at your own pace as you build endurance. Roberts instructs well, with plenty of safety and alignment tips, and she repeats the combinations enough for you to get them. But the camera has a...