knee pain

I had trouble with my knees and as part of my physical therapy he had me ride a stationary bike, so the first few months I that is what I did at the gym.  I tried the elliptical for 5-10 minutes and it killed my knee.  After doing only the bike for 4 months I was able to do the elliptical for 30-60 minutes and had no trouble with my knees.  This was BOTH my knee getting better and stronger AND all the weight I lost in those four months.  You might want to save the running for when your knees are stronger.