When it comes to cardiovascular training, the treadmill, eliptical trainer, stationary bike, stairmaster and the rowing machine all come up short when compared to the stair mill/step mill. What makes this piece of equipment superior to other cardio equipment is the additional strength and muscle development that you get in both your quads, glutes and hip flexors.

The stair mill also comes closer to being a "real world" movement than any of the other pieces of equipment which for me makes it more useful and challenging in a way.

If I had to describe the workout you get from the Stepmill, I'd have to say, "Oy!" This is one of the most challenging pieces of cardio equipment I've used. It's like climbing stairs, and climbing, and climbing, and climbing...

You see where I'm going with this? If you want to test yourself & get a great workout, this is it.