I LOVE the elliptical, and can work out for as long as 2 hours on it. It burns far more calories than the treadmill or the cycle if one ratchets up the level to, say, 20 over a period of time. I just can't run on the treadmill, and when I'm on the treadmill, I usually power walk at about 7.5 km/hr. Running tires me out in a matter of minutes, and I end up taking a longer break than the time I ran, so it's completely counterproductive. The elliptical isn't quite as tiring, and I get better results.