[galdosdi]

A lot has changed in school in 100 years. Less recess, less shop classes, and the average kid 100 years ago finished school after 6th or 8th grade, not after 12th or even "16th" (college) as today. They also probably got more other physical activity from doing chores that are now more automated, from possibly helping with a family farm or small urban household business, and from walking to and from school and other errands instead of being driven in an automobile.

A modern kid basically has to be put into sports or else they'll get about as little physical activity as an invalid in traction in the hospital nowadays.