How do you know when you are entirely in too good shape?

THIS SENTENCE IS DRIVING ME CRAZY!! There is something wrong with it, but I don’t know what. I wanted to say “too good of shape,” but we don’t say “You are in good of shape.” We only say, “You are out of shape.”

Somebody help!

This reminds me of when I was dating Jerry. He used to say thing like, “Get out the car now.”
I said, “Jerry, it’s ‘get out OF the car.” He was a teacher! He needs to understand this!
He looked at me in exasperation and said, “First you IN the car, then you OUT the car!”
I had to concede that disagreement!