may mean: The state of being physically active on a regular basis to maintain good physical condition.
- Physical fitness, a general state of good health, usually as a result of exercise and nutrition
- Cardiorespiratory fitness
- Fitness (biology), an individual's ability to propagate its genes
- Fitness competition, a form of physique training for women, related to bodybuilding.
- In mathematics and computer science, the degree to which a given function is optimized; see optimization (mathematics) or Fitness (genetic algorithm)
- The Fitness, an electric band.
- FitNesse, a web server, a wiki, and a software testing tool.