"健身" 的英文是 "fitness"。这个词来源于拉丁语 "facere"，意为 "做" 或 "完成"，和 "fit"，意为 "适合" 或 "适宜"。
例句：
I go to the gym to improve my fitness. (我去健身房提高我的健身水平。)
She is interested in fitness and healthy pving. (她对健身和健康生活很感兴趣。)
Regular exercise is important for maintaining good fitness. (经常锻炼对于保持良好健身很重要。)