Is running bad for your knees?

The short answer is maybe.

It depends on your weight, the mileage you run, whether you have any gait issues and the surface on which you run.

I have started running recently and to spare my knees I decided to run off road more. Now the knees are good but my Achilles' tendons get sore because of the hills and jumping ditches etc.

Increase mileage and effort super slowly. Be cautious.

Best wishes

Earle