I too find that when I run or use the elliptical I have more problems than if I ride a stationary bike. The only problem with that is that I used to be a competitive athlete and I am nowhere near that and may never be that again. I can lift weights with no problems. I used to be able to work out aerobically and not feel bad until the next day. Now, I feel like crap while I am doing it. I try to keep my heart rate around 140 on the elliptical and bike. I am nowhere near that while jogging (well over). I bought the kids a Wii fit for Christmas so I am looking forward to trying some different stuff. I do notice that when we play games that require a quick response, I cannot play. There is a game where you have to pick people who look the same and it only gives you a few seconds to find them. By the time I actually pick them out, the time is over! I feel that the learning curve is well out of my range. The kids think it's funny. I don't feel the same way!