What does to be as fit a fiddle?

The phrase "fit as a fiddle" means to be in excellent health or physical condition. It implies that a person's health is comparable to that of a fiddle, an instrument known for its taut strings and harmonious sound. When used to describe someone, it suggests that they are physically fit, energetic, and free from illness or injury. The origin of this expression can be traced back to the 19th century, where it was often used to describe individuals who seemed to be in perfect physical shape, like a well-tuned musical instrument.