The World's Strongest Weightlifter and World's Fastest Runner

A man entered a cool bar and ordered a milk shake, but suddenly he got a telephone call. So before attending call he took a napkin and wrote, ¡°The World's Strongest Weightlifter,¡± and left it under his glass to make sure nobody drinks his milk shake.
But he was shocked when he returned, the glass was empty. Now at spot of old napkin there was a new napkin with new writing that said:
"Thanks for the treat!"
"The World's Fastest Runner"