I am 48 and can totally relate to your situation. Keep up the lifting but I would suggest easing up on the weight for a while and see if that helps. I also try to balance cardio and weight training. I mostly use an elliptical for cardio as it is effective and easy on knees. You said that you go to a...

I am in total agreement with Fitoverforty. You really need to consider that some treadmills are better suited to walking and light jogging and some are meant to take the abuse of an avid runner. Fitoverforty is right on about watching the size of the running deck especially if you are a runner. You ...