At 290, I'm too heavy to resume my old love (running), as I don't want to blow out my knees or hips...I can run on the treadmill, buty have found I can get a great workout on the Elliptical machine without hurting my knees....

How does the elliptical machine rate compared to the treadmill as a good excercise machine to use for weight loss? How long should i use the elliptical machine each session? I'm a member of the local gym, and I usully spend a half hour on the treadmill or the elliptical machine, once every other day...Is that enough?
I'm shooting to loose 100 pounds

From what people are telling me....its which ever machine that you like better. People told me that they are bascially the same as far as cardio.

Look at my thread, (I believe its called) Help me decide

I think that whichever you can sustain better at a given heart rate is better - which may depend on you personally.

I like the elliptical because it lets me get my arms involved, and because my knees are pretty dodgy after trying to run. I can get my heart rate up and sustain for over an hour on the elliptical, so it works for me!

Personally, I find I can go for a longer period of time on the elliptical, as it is not as hard on the knees/shins. You can keep your HR up as long as the resistance is high enough.

Good news. It makes absolutely no difference! In fact, the main benefit of exercise is to maintain lean tissue (muscle, bone, etc.) while dieting. So, you wouldn't have to do either, if you did resistance training instead!

JMYHNY has it right, whichever you enjoy more. You'll be more likely to stick to it long-term. And if you start to like something else, don't be afraid to switch.

The others have addressed the first part of your question, so I'll chime in with the second part.

I would recommend that you start off slow, a half an hour every other day is probably a good start. Try that for a few weeks. Next, add an additional day in each week. Once that feels comfortable, then you can either add an additional day, or start upping the time on two of the days to 40 minutes, with the other staying 30. So on and so forth.

Goal here is a steady build of volume. Once your body has a good base, then you'd want to start working on implementing a bit of intensity into your routine. This is where it get's more detailed.

Also, don't be afraid to break things up and do 15 minutes of elliptical, 15 of treadmill. Adding some resistance training would also be highly beneficial.

I find that I lose more calories on the elliptical trainer than the treadmill, within a given period of time so I would recommend the ET. However, I have heard that the impact you get from running is good for bone development so EVENTUALLY, when you have lost some weight and your joints feel stronger, you might want to try varying your workout by using treadmills, cycles, etc. slowly and gradually.

As for how much you should do, I find that setting myself small goals helps. So I tell myself I will workout for 5 minutes on the elliptical trainer. As I'm approaching 5 minutes, I say to myself, 'hey I could keep going...' and I up it to 7 minutes... I keep doing this and quite effectively trick myself into doing up to 22 minutes on a single machine sometimes.

Hope this helps.

Im in the same situation as you. Ive used both the treadmill and the elip, and they both get me a very strong workout. Its true that elipticals may have a more fluid motion for your knees, but my opinion is that as long as youre raising your heartrate up and giving an honest effort then its really a preference issue.

Personally ive found that I can go much longer on an eliptical at a higher maintained speed than I can jogging on a treadmill. My 2cents. Good luck with the rest of your journey!