Old Sayings.

[zabado]

Why do we say fit as a fiddle ?.

[JJ109]

http://www.phrases.org.uk/meanings/40250.html

[dannyk13]

According to Brewer's it probably refers to a street fiddler who sways about energetically as he plays.

[gangesboy]

...and here's a third possible explanation
http://www.knowyourphrase.com/phrase-meanings/Fit-as-a-Fiddle.html

[Old_Geezer]

Never seen an unfit fiddle.

[zabado]

Thanks guys. Today i'm a little bit wiser.

[Khandro]

I prefer "fit as a flea";
'How high could a flea jump if it was the size of a human?
"Fleas can jump over 80 times their own height, the equivalent of a 6 foot tall human jumping over a building 480 feet (more than 1 and a half football fields)high!"'