How do you use fit as a fiddle in sentence?

Here are some examples of how to use "fit as a fiddle" in a sentence:

Informal:

* "After a good night's sleep, I feel fit as a fiddle!"

* "Don't worry about Grandma, she's 80 but still fit as a fiddle."

* "He's been training hard and is now fit as a fiddle for the marathon."

More formal:

* "Despite his advanced age, the gentleman was as fit as a fiddle and enjoyed daily walks."

* "The athlete's rigorous training regimen ensured he was fit as a fiddle for the upcoming competition."

Figurative:

* "The old car, despite its age, was running fit as a fiddle."

* "The company's new software was working fit as a fiddle, with no glitches or errors."

Remember, "fit as a fiddle" is an idiom meaning someone is in good health and full of energy. It's generally used in informal settings, but can be used in more formal contexts as well.