I hear ya, dude, though I didn't take the long hiatus from riding. I'll be 66 in a few months, and my knees have never been able to tolerate running. My short but frequent and strenuous rides have kept my legs strong, my BP Under control, and my resting pulse at 50, all without medications. I refuse to be like the sedentary, one-foot-in-the-grave geezers I see all around me. It's a state of mind, and it drives the physical response.