The body needs the rejuvenation that comes from exercise. Walking in the fresh air can be exhilarating and refreshing. Properly directed running can also have some beneficial effects. Simple sit-ups or sports activities can also be helpful.
We lived, until I was 12 or so, in communal apartment with five different families and the same kitchen, in two little - my brother and me and my parents. It was hell, but it was a common thing. My father was not general or admiral, but he was colonel. He was teaching in military academy military topography.