Cybex 625AT Arc Trainer, not all cross trainers are created equal. With the Cybex 625AT Arc Trainer you get more results in less time. Research shows that the Cybex Arc Trainer burns more calories than any other cross trainer or elliptical cross trainer tested. The science behind the Arc Trainer’s big calorie burn is the Arc motion. It engages the right muscles ’ quads and glutes ’ that demand lots of energy from the body when they are called upon to work. That means big calorie burn. And ... because the Arc is demanding of the muscles ’ not the joints, it can be used longer without putting a strain on the knees, hip or back. Train for strength, power, endurance, cardio, and weight loss. The Cybex Arc Trainer offers broad incline and resistance ranges which mean it is really 3 machines in one. At the lower incline levels, the ’glide’ is a cross country skier. In the mid-range levels, the motion is a ’stride’ (like an elliptical except with proper positioning). At the high levels, the ’climb’ of a stepper or climber. Glide, Stride, and Climb. And ... lots of programs also make the Arc Trainer fun to use. And no more ’elliptical knees’. Unlike other cross trainers on the market the patented Arc pattern of motion allows the hip and knee to move synchronously while the foot stays under the knee reducing joint pains and providing a more comfortable workout.