biologic rhythm

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Related to biologic rhythm: circadian rhythm, biological clock

biologic rhythm

Etymology: Gk, bios, life, logos, science, rhythmos
the periodic recurrence of a biologic phenomenon, such as the respiratory cycle, the sleep cycle, or the menstrual cycle. Also called biorhythm.


Alternative medicine
A hypothetical biologic rhythm, which is said to be set at birth.
The biorhythm theory was first proposed by H Swoboda and W Fleiss, a contemporary and colleague of Sigmund Freud; proponents of the biorhythm theory believe there are three distinct cycles: a physical cycle of 23 days—which corresponds to co-ordination, immunity, self-confidence, and strength; an emotional cycle of 28 days; and an intellectual cycle of 33 days, all of which are defined by a sine wave; “critical periods” are believed to exist as an individual crosses the middle of a cycle, either from a high to a low, or vice versa.

Cyclical variations in physiologic and biochemical function, level of activity and emotional state. Circadian biorhythms have a cycle of about 24 hrs; ultradian rhythms are < 1 day; infradian rhythms are greater than one day and may be up to weeks or months.
References in periodicals archive ?
Strategies to help sleep-disturbed patients get in tune with their biologic rhythms include taking naps, the use of light-boxes, and the use of melatonin.
Light boxes, available in various forms and sizes, may help travelers shift their biologic rhythms to function at their best.
However, biologic rhythms vary with the individual, and laboratory research has shown that individual biologic rhythms impact cognitive performance.
Strategies that are aimed at helping sleep-disturbed patients get in tune with their biologic rhythms include taking naps and using light boxes and melatonin.