Elliptical vs. Treadmill

I have been spending 65 minutes per day on the elliptical machine, burning around 600 calories.  I have bad knees, so I thought that this would be the best route to go.  However, yesterday brought a slight dilemma to my attention.  ESPN was on the TV next to the treadmills.  So, I thought to myself that I would walk fast with a steep incline on the treadmill.  That is what I did.  I found myself sweating after 10 minute.  This does not happen to me on the elliptical.

So, my question is:  Which of the two gives you a better work out?  I have never sweat on the elliptical the way I did on this treadmill yesterday.  I don't know what that means, but I pushed myself on both.  So, I would appreciate any input.

Thanks!

I also have bad knees and typically stuck to ellipticals but switched to a treadmill one day when all of the ellipticals were in use...I did the same thing and had the same results.  Now I generally try to use the elliptical for 30 minutes and then switch over to a treadmill with a steep incline for another 30 minutes depending on how tired I am. I feel like the elliptical warms me up for the treadmill action, plus I like to change it up a little and my gym doesn't allow you to spend more than 30 minutes on any machine.

I find I can get a better cardio workout from a Precor cross ramp machine (it's sort of an elliptical that you can add resistance to) than I do with either a conventional elliptical or a treadmill. But your mileage may vary.

i have a treadmill at home, so i'm kinda limited in what i use.  but my guess is that your best bet would be to switch it up...maybe alternate days with one day on the treadmill the other on the elliptical?

The elliptical is my favorite machine because it seems like it burns so many more calories. At the gym though I noticed that some people weren't doing the exercise correctly. One thing to consider....your body isn't supposed to bounce up and down when you are on the machine. The key is to try to keep your body pretty stable and really work your legs. (think of it more as sliding your legs forward and backward as opposed to "running") The calorie count can be misleading because it assumes you are using the machine correctly. If this makes sense and you haven't already been doing it this way try it and believe me you will notice a difference. It gives quite a burn.

Don't get me wrong, "running" on the elliptical machine gets your heart rate up, but I doubt that it burns as many calories.

Hope this helps!