Stamina comes naturally when you are in your teens and 20s. Assuming you are in good general health, in your 30s and later it's a matter of staying in shape and

Stamina comes naturally when you are in your teens and 20s. Assuming you are in good general health, in your 30s and later it's a matter of staying in shape and eating well. Carlos Lopes of Portugal was 37 when he won the Olympic Marathon ('84, Los Angeles). If that's not stamina, I don't know what is.