I've had multiple back surgeries and I'm more out of shape than ever before. I needed exercise that I could do anywhere, and that would not hurt my back. In the past I'd try taking on too much at once and quit after a short time. Although this is my first week, I feel like I can do these workouts and get good exercise without over doing it. They are fairly short and simple, but are definitely effective because I am sore in a good way. I'm looking forward to seeing what changes come over time.