Another principle in the energy section is that All…
Another principle in the energy section is that All tasks need energy expended on their behalf. To the extent that a task can be automated, that conserves energy and allows you to keep that energy for other tasks. To the extent that an individual creates habits, those habits conserve energy because it is an automation of the tasks.
— from Fuel (Energy)
In the book
Refuel the physical tank first, because it carries the others. Move your body — exercise is the fastest way to alter a depleted state and sharpen the mind; when the gauge spikes into panic, take four or five long, slow belly breaths, which calm the whole system at the source; and never undervalue sleep and food, the plainest refuelers there are. Spend the mental tank on purpose. Attention is the single most essential mental resource you have — it decides what you even notice, and your brain processes everything at a real cost, so automate the small, repeated decisions to save the fuel for the ones that matter. In most choices the goal is not the perfect answer but a good-enough one — spend only the energy the decision truly warrants — and let well-built habits run themselves, since a little useful mindlessness frees the mind's scarce fuel for what truly needs it. — Fuel (Energy)