There is a relationship between enthusiasm & optimism, and energy that fuels productivity.
We also need rest and recovery. Especially leaders. Fight against the feelings of guilt over taking breaks and getting appropriate rest.
I find it intriguing that most but not all our units of time in the western world are derived from astronomy:
A year Earth orbits the sun
A month Moon orbits the Earth
A day Earth rotates 1 time on its axis
Hours and seconds Convenient time intervals of a day
What’s missing? A week. There is no astronomical basis for a week. In the Judeo-Christian heritage we have a week from biblical revelation: “Six days you shall labor and on the seventh day you shall rest.” This is a command from God. As a student of the Bible I can tell you of a consistent pattern: We are commanded to do the things we do not naturally do, but are good for us.
Rest. Recover. This is not leadership laziness.