it is a superlative because it ends with "est"
fitter, fittest
Fitter is the comparative form of fit, and fittest is the superlative.
fitter, fittest
The comparative form of tight is "tighter". The superlative form is "tightest".
The comparative and superlative of fit are: fitter and fittest. I am fit and my 40-year old dad is fitter, but his brother is the fittest of us all. The girl complained, "I can't get fit, let alone fitter or fittest!"
The degrees of comparison for the adjective "fit" are positive, comparative, and superlative. In the positive form, it is "fit." The comparative form is "fitter," and the superlative form is "fittest." These forms are used to compare the fitness of different subjects.
The Fittest of the Fittest was created in 1983.
Fittest
The Fittest Selection was created in 1987.
Survival of the fittest
The fittest athlete is the one that trains the hardest.
Emmett Cullen is the fittest and Jasper has the strength in him because he was in the army.