The Oxford Thesaurus An A-Z Dictionary of Synonyms - fitness n.

1) aptness, appropriateness, suitability, suitableness, competence, pertinence, seemliness; eligibility, adequacy, qualification(s) : There is some doubt about Henryson's fitness as a leader. 2) health, healthiness, (good) (physical) condition, vigour, well-being, (good) shape, (fine) fettle, tone, wholesomeness, salubriousness or salubrity: Tony is a fanatic about physical fitness and exercises daily.