Flex'em baby.

Trust the Europeans to do something like this.

Self-conscious about what you wear while working out? A Dutch gym plans to introduce "Naked Sunday" for people who like to huff and puff in the buff. Patrick de Man, owner of Fitworld gym in the town of Heteren, said he got the idea in part from two of his customers who are avid nudists.

"I heard that some other gyms are offering courses on 'pole-dancing' as a sport, so I thought: Why not bring something new to the market?" de Man said. He said the response had been overwhelming — positive and negative.....

They really aren't too concerned about nudity, are they? :)