保持身材英语是指 "keep in shape" 或 "stay in shape". 这个短语源于英语中"shape"这个单词，指的是一个人的体形或体型。例句如下:

I try to go to the gym at least three times a week to stay in shape.

Eating a balanced diet and exercising regularly are key to keeping in shape.

She's been running every morning to keep in shape for the upcoming marathon.