Are these things for real? I recently started using one at the health club and it just seems too easy...I'm able to burn calories at the same per minute rate as I would if I was jogging on a treadmill. Since I'm significantly overweight, the jogging causes considerable shock to my feet, ankles and knees. When I step off the eliptical trainer, I feel none of the throbbing in my joints like I do on the treadmill. It just seems too good to be true.