Calisthenics is the usual American spelling of callisthenics (British English often keeps the extra l). It means exercise you do with your own body: push-ups, sit-ups, squats, jumping jacks — strength and looseness without gym machines, and often without weights. The name was built from Greek for “beauty” and “strength,” so the old picture was graceful, strong movement, not only sweating.

Calisthenics is the usual American spelling of callisthenicsCalisthenics是callisthenics常見的美式拼法 (British English often keeps the extra l)英式英文常常保留多一個l。It means exercise you do with your own body它指的是用自己身體做的運動 push-ups, sit-ups, squats, jumping jacks伏地挺身、仰臥起坐、深蹲、開合跳 strength and looseness without gym machines不用健身器材就能練力量和柔軟度 and often without weights通常也不用啞鈴這類重量。The name was built from Greek for "beauty" and "strength"這個名字是從希臘文的美和力量組成的 so the old picture was graceful, strong movement, not only sweating所以原本的畫面是優雅又有力的動作，不只是流汗。

Though actually, American schools and coaches also use it for a short warm-up of simple moves, which can sound rather official or a little old-fashioned; many younger people just say bodyweight training, or name the move. In parks you may also hear it for harder bar work (pull-ups, muscle-ups). So the word stretches from gentle PE to serious street workouts.

Though actually不過其實 American schools and coaches also use it for a short warm-up of simple moves美國學校和教練也會用這個字指簡單動作的短暫暖身 which can sound rather official or a little old-fashioned聽起來可能有點官方或有點過時 many younger people just say bodyweight training, or name the move很多年輕人乾脆說徒手訓練，或直接講動作名稱。In parks you may also hear it for harder bar work在公園裡你也可能聽到它指比較難的單槓動作 (pull-ups, muscle-ups)像引體向上、馬肌。So the word stretches from gentle PE to serious street workouts所以這個字的範圍從溫和的體育課一路延伸到硬派的街頭健身。

This one-l spelling is the one American books and apps will show you.

This one-l spelling這個只有一個l的拼法 is the one American books and apps will show you是美國書籍和app會給你看到的那種