NIOSH Training for Nurses on Shift Work and Long Work Hours

Regulation of Sleep: A Simple, Two-Process Model

Understanding basic principles of sleep regulation is helpful for determining strategies to adapt to shift work and long work hours.

Humans are “hard-wired” for sleeping during the night and being active during the day. Researchers explain that sleep regulation has two components:^19-21

1. Build-up of homeostatic sleep drive
2. Circadian rhythms

These two components interact to determine the time when we go to sleep and the time when we wake up, as well as the stability of waking neurocognitive functions (e.g., how well we feel when we are awake).