crunch的动作，需要肩膀往腰的方向沉，就是只是上腹部的肌肉收缩，好像被人从前面打击一样，所以眼睛最好看天花板

来源: 40er 于 2019-04-25 12:26:09 [博客] [旧帖] [给我悄悄话] 本文已被阅读：次

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