Circadian rhythms of autonomic parameters during mental and physical activity.

The structure of circadian rhythms of autonomic parameters was monitored during working week in subjects occupied by physical and mental work. Differences in the rhythm structure depended on the work type and schedule, as well as on the subject age. Hard physical work was associated with biphasic changes in the autonomic nervous system functioning with dominating sympathetic and parasympathetic components in the beginning and at the end of the working week, respectively. Intensive physical work caused rhythm synchronization: the acrophases were shifted to 14.00 and the amplitude of daily oscillations was high. Mental activity with individual working schedule resulted in chronic desynchronization most pronounced in subjects over 30.