Two old men sat on a bench outside a nursing home having a chat.
"How are you, Richard?" asked George.
"I'm not feeling too good today, I'm utterly exhausted," replied Richard.
"I've pulled a muscle and it's killing me."
"I'm surprised that a pulled muscle makes you feel so tired," said George.
Richard yawned and said: "Well it does if you pull it a hundred times in one night"!