Endless Energy (get the book or audiobook) by Peter Hollins is a guide to becoming insanely energetic.
How do we improve our sleep?
The first step is to understand your sleep biology, and the next is to learn to work with it so you’re waking up refreshed each morning and with a full “tank.” Your circadian rhythm is your body’s own inbuilt sense of when to wake and when to sleep. Parts of your body perceive and respond to changes in light around you and move through cycles, with physical and behavioral changes occurring over a twenty-four-hour period.