Started bike racing at 13, raced on and off up to my mid-30s, have continued training-level riding most days to present day, at age 68.
Never stretched, never took supplements or aspirin or ibuprofen, never lifted weights, etc. Since junior high, no athletic activity other than lots of cycling.
Any occasional knee twinges that I get disappear in the course of my usual hilly 3-hour-plus rides on my road and track bikes.