I was a 3:47 1500 m runner in HS, a very good student, and had modest success in track in college. I even managed to get 4th in my major conference XC meet my senior year-my first year I made the XC team.
I went to a high end Graduate School (Ph.D. Economics) and was fairly unhappy with my educational background from my giant state school- I was aware that despite my grades I put very little into school as I was running and traveling all the time. At a big school, a clever person could cut a lot of academic corners (even as a math major).
I refused to train twice a day as it cut into my study time and work time (scholarship only covered tuition, room, and board and my parents were long gone).
Looking back, I wish I went to an excellent DIII school that had a great coach and would allow me more time to actually be a student.
My advice for runners who are academic types is to seek out these schools. The job market is harder today for young people and whole lot less tolerant of the folks who have flaky majors that many D1 athletes take-marketing, industrial relations, etc. Even my math major would be a whole lot less valuable today.