One of my first jobs at my old company was working with the credit manager, Meyer. Meyer was an interesting guy — really ahead of his time in the early seventies. One of the things that he did was to drink six to eight glasses of water a day. Another one of the tricks that he used for managing his age (being in his late sixties) was to take what he called a power nap during his lunch break. He explained that the nap gave him more energy when he got back to work.
As years went by I began working very long days. One day I stumbled across an article about the people of Japan. It was about how they were very industrious and worked extremely long days, which included required socializing with clients at the end of the day. One of the things they did was to build a room at their offices for people to take power naps — a 15 to 30-minute nap each day. This restored their thinking by giving both the body and mind a chance to rest and reset.