“I also have some bad knees from overdoing it in HS and don’t want to make them worse.”
Aah. Well, that explains it. I have similar troubles for similar reasons. I used to run cross country and did every track event from the 400 onwards. Used to race against the sprinters to the same folks I had to face in cross country in the 3000. Did that for two years - that’s really too much to do in a meet.
Mostly I swim these days. Keeps me fit. Last I ran, I did a 10k in around 45 minutes, so that should give you an idea of where I used to be at my best.
.Same here, CC for 4 years and track for 3. If I run today it's mostly on the local HS rubber track. We live near a state park with 15 miles of grassy hiking trails so we do run on with cross hiking/running shoes. Try to stay off of pavement as much as possible.
My knees are not causing me major problems but they do ache somewhat at times.. I take GNC Tri-Flex which has really helped.