Buy your boy a book of basic offensive or defensive theory. A lot of high school coaches dont realize the kids are a lot smarter than they are so they dont bother with that stuff but is probably higher yield than running up hills for high school kids. Just like anything else football is more mental than physical. Even the physical is more balance and position than strength. Send him to the weight room too though.
My first day of contact practice (weighing 102 lb) in high school I ran right over a future yewt nt who was twice my size.
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