This is an outstanding product. I don't always have the time or the motivation to get to the gym, but the Sprintmaster makes working out simple and convenient. The initial construction was simple with the instructions provided and it folds up after each work out and easily fits under the bed for out of the way storage. Running outside or on the treadmill can be very harsh on your knees and that's why the sprintmaster is so much better. There is no impact and the machine effortlessly glides with your motions. If you lean forward, you can also work your arms. If you lean back, it focuses more on your legs. It truly is a total body workout system and the DVDs that it comes with have excellent workouts for people of all fitness types.