Hi. I had knee surgery due to a torn lateral meniscus about 4 years ago. All the posted advice is great and is what I followed to ease back into running, cardio, and resistance training. In addition, listen to your body and then do what it's telling you to do. I still experience a bit of pain sometimes. For me, it's either when I'm running too many miles without appropriate rest periods or, most often, when I'm not focused and I'm not using proper form. When I catch myself, focus, and run properly, the pain dissipates within a few minutes. Other times, that doesn't work and I know to stop running. Another important thing is to learn how your particular body functions post-surgery. For example, I have traced my knee pain to weaknesses in other muscles on the same side; mainly my gluteus maximus. Doing a few simple hip extensions before and after running always does wonders for me. Pay close attention to your body and a lot will be revealed. Best of luck!