Official websites use .gov
A
.gov website belongs to an official
government organization in the United States.
Secure .gov websites use HTTPS
A lock (
) or https:// means you've safely
connected to the .gov website. Share sensitive
information only on official, secure websites.
Sleep as a state of maximally reduced energy expenditure. This is the result of sleep-imposed immobility and absent nutrition, which eliminates the energy cost of activity (activity-related energy expenditure) and food-related thermogenesis (thermic effect of food), and a 20–30% decrease in resting metabolic rate (RMR), because less energy is needed to support brain function, sympathetic activity, breathing, circulation, and core body temperature during sleep.
