I tried running again, but everytime I do I get a bad cse of 'runner knee' so I have given up on running. It's weird though. Knee intensive things like squash and ninpo are not a problem at all. I can do them many times per week intensively. But after a mile of running my knees force me to stop.

Doesn't matter anymore. I am happy enough doing ninpo and jujutsu several times per week and improving my physique that way.

As for ribbing: not really. there's no time like the present to start doing something. Go for it Alan.