I love the Proform Treadclimber. It makes me sweat and it makes me move. It utilizes both your legs and your arms when you use them in a swinging motion. I would recommend this machine for anyone who wants a challanging workout. The gym I go to has only one and there is usually a line waiting for it. There is a 30 minute time limit. It has levels that you can adjust for speed and for the climber to be more harder.