The Gazelle is a very controversial piece of exercise equipment. That's not surprising, given the wide disparity between calories-burned estimates that are bandied about with respect to the Gazelle. Short of hooking yourself up to a separately-calibrated heart-rate monitor, it's pretty difficult to get a reliable estimate of how many calories you've burned. I'm not sure why, but there must be something about the Gazelle that makes it particularly prone to this high level of variance.
I had a very early version of the Gazelle. (Just a short aside: It's broken now, but I don't think there is much to be learned from that, because it seems clear to me that the distributor of the equipment learned from the repairs I made them pay for while it was under warranty, and have presumably made the product better. Mine broke for the last time after the warranty period was over -- and by then I had come to the conclusion that it was no great loss, as I had found more effective ways, IMHO, to exercise.)
I did try to calibrate how effective it was at burning calories using a heart-rate monitor, and comparing the results I got to the results I got with other exercise. At best, I was able to burn 250-300 calories per hour (I was at about 240-200 pounds, back then). I contrast to this my treadmill, which helped me burn a minimum of 300 calories per hour at the easiest configuration and relatively slow speed. A stationary bicycle, my The Firm practice, and my vinyasa yoga practice all burned far more calories per hour.
However! as I said earlier, I had a very early version of the Gazelle. One other thing it seems the distributors of equipment like this have learned is that for these devices to be effective, they've got to apply resistence to the exercise. That will make the difference between 200 calories per hour or 400 calories per hour, or 800 calories per hour, or 1200 calories per hour.
Regardless, in general, please be very careful about where you get your calories-burned estimates. I deluded myself for years with respect to that sort of thing. A good rule of thumb, based on my experience, is to always use the lowest estimate you can find. If that doesn't satisfy you, then invest in a heart-rate monitor and get a clearer picture of just how much effort you're exerting while exercising. However: Beware even of the calories-burned estimate you get from heart-rate monitors. I found that mine consistently read 30% higher than actual! It is critical that you calibrate such numbers against alternative means of measuring calories-burned, and always go with the lowest estimate you can find.
I want to chose the site over the Gazelle computer...
