(When I travel to places like the Sierra, I am often the only person who goes for an apparently pointless jog in the morning to the amusement of the locals.) But nearly every day of their lives, hunter-gatherers and subsistence farmers engage in hours of hard physical work. Because they lack cars, machines, and other laborsaving devices, their daily existence requires walking many miles in rugged terrain, not to mention doing other kinds of physical labor by hand like plowing, digging, and carrying.
