This weekend the local boy scout troop is doing their annual overnight Bataan Death March: elementary boys (and girls as the scouts here are open to both sexes) will be marching 30km; junior high schoolers, 60 km; and high schoolers, 100km.
Out of curiosity I checked what kind of mileage a Marine recruit puts in over his 13-week-long bootcamp and came up with about 200 miles (320km), which is nothing compared to what these Japanese kids are doing in one night.
Welcome to Sparta!
Note: Looked into the “Bataan Death March” and learned that, one, it was about 100 km long, give or take 5 kilos, two, half of it wasn't on foot, but in rail cars, and, three, it took place over a period of about three days. It always sounded like hell on earth to me—and I'm sure it wasn't easy (heat, lack of potable water)—but, geez, little Japanese boys and girls here are doing it overnight with little more than a water bottle and a couple of o-nigiri. These kids are tough!