To exercise or be physically active; to move one's body — can refer to anything from light movement to formal workouts.
毎朝、公園で軽く体を動かしてから出勤する。
Every morning I do some light exercise in the park before going to work.
週末は家にいるより外で体を動かしたい。
On weekends I prefer to be active outside rather than stay at home.
長時間座った後は少し体を動かしたほうがいい。
It's better to move your body a bit after sitting for long periods.