I think I'm a fairly fit 48 year old male, my cardio is pretty good from cycling and despite being 5'10" I'm a svelte 67kg. My issue is my knees, if I jog for more than about 7km I get serious pain on the inside of my knees (either knee). I think one of my issues has always been that my heart and lungs can run but my joints can't. So I'm thinking that instead of trying to run longer I should just try running less but more often. I began slow jogging just 1 mile each night and I'm thinking I will start doing another mile in the morning. It's my theory that in time - perhaps six months - my knees might have got used to the light but regular pounding and I'll eventually be able to increase the distance. I wondered if anyone has a suggestion, does my plan sound viable ?