In their small village, a couple was famous for the husband being 102 years old and his wife being 98 years old, and both in terrific condition, working their farm every day and having the bodies of much younger people.
One day, a visitor to the village, curious about the couple, approached the old man at his farm. The old man was cutting wood without a shirt on, sweat glistening on a body that seemed to belong to a man half his age.
The visitor introduced himself and asked the old man: "I hear you are 102!"
"That's correct." said the old man with a smile.
"Wow, I must say, you look in amazing shape!"
"Thank you." Said the old man humbly.
"Do you mind if I ask-"
"-How am I this healthy at my age?" finished the old man. "Help me carry this wood back home and I'll tell you."
The visitor agrees and they make their way inside.
"You see," said the old man, "I've been married for 75 years. Now, when we got married, I made a little arrangement with the wife. Every time we have an argument, the loser of said argument must run for 5 kilometers. Seeing as we have a pretty typical marriage, I've been running 5 kilometers almost every day for 75 years! That's why I'm in the great shape I am."
"But if that's the case," said the puzzled visitor, "how come your wife is in such great shape too?"
"Well," smiled the old man, "she usually runs after me to make sure I finish the whole five."