I've been a serious runner for nearly 20 years. I was running over 100 miles a week for much of that time, but have dropped that down to 40-50 for the past 2 years or so. In that time I've also had to run almost entirely on the roads. Lately, both my knees have started to ache below and behind the knee cap. I've taken substansial time off (3 weeks no running) and the pain has not gone away. It feels like tendonitis of some kind, but is not responsive to any anti-inflams that I have tried over the past 4-5 months. I haven't had the time to see a doc or sports med guru, but I thought I would get some feedback from the professional armchair docs here at Let'srun. Any ideas? Have I run out of mileage on these things or is there some simple cure? Yes, I've changed shoes several times since the knees began to bother me.