Probably not the answer everyone is looking for but mine request would fall under the history of sport during classroom sessions before practice.
My theory is that you can plug training philosophy into Lydiard, Daniels or whomever is at the top of the game and, respectfully, come out relatively equal.
The Late Joe Newton (Northwestern '48) and a number of Phy Ed teachers out of the post WWII period that went to flagship schools had to go through curriculums that taught these things. I dont think phy ed teachers do this now. You can hear it in Joe Newton's talks specifically about veritas and virtue though.
Why we humans run
Where our sport came from
Why we have sport
Why sport is important
The functions of sport
The Virtues & Sport
Educational Philosophy behind scholastic sponsored sport (antiquity and beyond)
Some of you might think this is nuts but this stuff is also really deep and educational which is perhaps a primary function of scholastic-backed cross country.
I absolutely would have eaten up an early September classroom session in the 30 minutes after school talking about Royal Hunts and the SED Festival then heading out for a tempo run. Or Platonist theory on gymnastik cultivating the virtue courage and concluding with a quote of the day. Or an early August practice where the game of Hares & Hounds is played that included a backstory and history of the game beforehand. Or special olympic caliber athletes in the modern era and their triumphant journeys.
Maybe even a little music so the chills are sent up spines. The daily lessons refracting from their souls before they go out for the days workout.
While their "window" is open to sport their educational capacity may flourish as they learn about themselves on a much deeper human level.