Free-running sleep

Free-running sleep is sleep that is not artificially regulated. It is used as a form of chronotherapy that can help to cure some sleep disorders. Most people in the industrial world cannot afford free-running sleep. Only a small part of the population can sleep in a perfect 24 hour cycle and in synchrony with the schedules demanded by work and family. The most typical violation of free-running sleep is the use of an alarm clock. Another violation is staying awake past one's accustomed bedtime in spite of drowsiness. (Staying up late when one is not sleepy does not violate free-running sleep.) Going to sleep too early (e.g. to force longer sleep before early arising) may also disturb the free-running sleep cycle.