Free Running Rhythm

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Definition - What does Free Running Rhythm mean?

Free running rhythm refers to the circadian rhythm assumed by an individual when their sleep is not guided by external cues. In other words, it is the cycle of sleeping and waking that a person's body naturally adopts when there are no external time cues such as light or waking-sleeping activities present. For most individuals, their free running rhythm period will last approximately 24 hours.

The term free running rhythm may also be spelled as freerunning rhythm or free-running rhythm.

SureHire explains Free Running Rhythm

The term free running rhythm is often used to refer to individuals whose natural circadian rhythms don't adhere to a 24-hour cycle. In some cases, this free running rhythm results in a delay of the circadian cycles. This delay can result in a phase shift of an hour or more, causing the person's waking and sleeping times to gradually work their way 'around the clock.'

For most individuals, the circadian rhythm consists of an approximately 24-hour cycle. However, for some individuals, their natural or endogenous rhythm does not track this 24-hour time period. For example, individuals who are blind and cannot detect natural or artificial light often have free running sleep rhythms. As a result, these individuals may experience insomnia or daytime sleepiness.

When a person's sleep-wake cycle does not conform to the 24-hour period, they are said to have disordered sleeping. Whether due to a lack of external stimuli, a neurological or genetic disorder, or other causes, a free running rhythm that is abnormal can cause chronic sleep deprivation, fatigue, insomnia or depression.

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