I did the elliptical for 30 minutes today (I was short on time, woke up late). Yesterday I tried this new machine...the ARC trainer. Anybody heard of it? FANTASTIC. I just got a gym membership last week. I've been hitting it everyday except Tuesdays and Thursdays because I work and go to school on those days (17 hour days). I have bad knees, but I love cardio, and I have found that bikes and ellipticals are okay for me, if I use some resistance. Also, the ARC trainer (from their website) says that they work for people with bad knees. I need to do some strength training. I go to the gym with my BF though, and hate lifting weights with him. We're both too competitive, and he can lift much more than me. LOL