Khan and His Shrines warn that this so-called "Land of the Freak" is where only the strong survive, but it's a strength that can't be measured in muscle.

NPR: King Khan And The Shrines: 'Freak' Show

In Renaissance Italy, it turns out, there was no end of advice as to how to get them: would-be parents of sons should eschew strong drink, endure abstention to build up their strength and then have intercourse early in the day.

ECONOMIST: Renaissance advice books