expression, godan verb (-su)
sit up; raise one's upper body
Describes the action of lifting the upper body from a lying or reclining position, often into a sitting posture.
彼はベッドで上半身を起こして、水を飲んだ。
He sat up in bed and drank some water.
腹筋運動
When raising your upper body during sit-ups, be careful of your lower back.