Skip to main content

Entrainment

Meaning

Entrainment, in chronobiology, is the essential process by which an endogenous, self-sustaining biological rhythm, such as the circadian clock, is synchronized to an external environmental cycle. This mechanism ensures that an organism’s internal physiological processes, including sleep-wake cycles, hormone secretion, and metabolic activity, are optimally timed with the planet’s 24-hour light-dark cycle. A failure of proper entrainment, often seen with shift work or rapid trans-meridian travel, results in circadian misalignment and a state commonly known as jet lag.