Exactly that.
How dodgy are they? How do you cope with it?
I love cycling but have had one hip replacement and am getting my second next month. Right now, I'm walking on crutches as the joint is crumbling but I had a sneaky ride on DH's bike the other day (I'm talking about a few hundred metres - no distance at all) and I had no pain. I was so excited!
DH is concerned - he sees the state I'm in when I've walked too much (hardly any distance is too much for me right now) or when I've been on my elliptical trainer, and he thinks I shouldn't do it, but just wait till I've recovered (4-5 months from now!).
But I'm getting almost no exercise, I'm comfort eating because I'm bored and feel sorry for myself and I'm getting quite considerably overweight.