Healthy is another word for fit.
exercise
ill-fitting.
Indigestible
Fit.
The word is edible.
cry or pitch a fit
The word, "trauma" seems to fit.
Exchange, and replace fit this description.
tyrantism
'Wrap' would fit.
The noun form of the adjective 'athletic' is athleticism.The word 'athletic' is the adjective form of the noun athlete.
Another word that can be used to replace the word fanatical is the word manic. You could also check a thesaurus for different options, that may fit what you are writing better.
Fit is the correct spelling for the word fit.