This is a good exercise to work your lower and upper body mass simultaneously.  This is would be considered a "Full Body Toning" exercise because you use a lot of your body mass. If you are overweight or overfat you could benefit from doing full body exercises during your whole weight training workout. You will get the most "bang for your buck" and possibly spend less time in the gym. Personally I would love to spend as little time as possible in the gym. Don’t let your knee move forward during this motion if you want to work your glutes, quads, and hamstrings correctly. You can also do this as a general style warm up if you are already in shape. Personal Trainer Mike Behnken, MS, CSCS