来自fit, 合适的，得当的。后用来指身体上适宜的，健康的。

1. The emphasis is on developing fitness through exercises and training.

重点在于通过锻炼促进健康。

2. He has a new fitness regime to strengthen his back.

他有一个增强背部力量的新健身计划。

3. There is a debate about his fitness for the highest office.

针对他是否能胜任最高职务展开了争论。

4. I'd like to join an aerobics class to improve my fitness.

我想参加有氧运动训练班来增强体质。

5. Fitness is relative; one must always ask "Fit for what?"

“适合”是相对而言的；应该常常问一问“适合什么？”