Fixx became a runner because he was told by docs that his heart was bad and that he was at death's door. The cardiovascular benefits of running probably prolonged his life.
I loved to run but my joints and bones won't support it any more; I'm having a hard time finding an alternative.
d.o.l.
Criminal Number 18F
There's a thing you might try that involves all the motions of running but is staying in place and rocking onto the balls of your feet. Not the same workout but easy on the joints and doable nearly anywhere.