What is the Origin of Physiological Deceleration Point?

This concept is derived from chronophysiology, which studies the rhythmic changes in human biological functions. It represents the temporal marker where the dominant hormonal and neural signaling shifts from wake-promoting and catabolic to rest- and repair-promoting and anabolic. This deceleration is intrinsically linked to the declining phase of the cortisol rhythm and the approaching onset of the melatonin surge.

What is the Mechanism of Physiological Deceleration Point?

The deceleration is driven by the decreasing activity of the suprachiasmatic nucleus's alerting signal and the natural, programmed reduction in core body temperature. Circulating levels of stimulatory hormones, such as cortisol and certain catecholamines, naturally decrease as the day progresses. This hormonal shift facilitates a parasympathetic nervous system dominance, preparing the body for sleep by reducing heart rate variability and slowing psychomotor speed.

Physiological Deceleration Point ∞ Area

Physiological Deceleration Point

Meaning

The physiological deceleration point is the specific time of day when an individual’s core physiological processes—including metabolic rate, cognitive function, and physical energy output—begin a predictable and measurable transition toward a lower state of activity. This is a critical transition, distinct from the immediate post-meal dip, as it marks the beginning of the body’s evening phase preparation. Recognizing this point is crucial for optimizing the shift from diurnal activity to nocturnal repair and regeneration.