Accession Number : AD0692748

Title :   CIRCADIAN RHYTHM IN INDICES OF HUMAN PERFORMANCE, PHYSICAL FITNESS AND STRESS RESISTANCE,

Corporate Author : DEUTSCHE VERSUCHSANSTALT FUER LUFT- UND RAUMFAHRT E V BAD GODESBERG (WEST GERMANY) INSTITUT FUER FLUGMEDIZIN

Personal Author(s) : Klein,K. E. ; Wegmann,H. M. ; Bruener,H.

Report Date : 27 OCT 1967

Pagination or Media Count : 8

Abstract : In order to estimate the existence and magnitude of rhythmic day-night variations in human performance, physical fitness and stress resistance, the following variables were measured every three hours over a full day-night cycle: The reaction time and its individual constancy, the maximal psychomotor coordination ability, the Schneider index, the predicted VO 2 max, the cardiovascular responses to tilting, the 'time of useful consciousness' at simulated altitude. The twenty-four hours were divided into two experimental sessions so that limited sedentary activity could be maintained between the tests. All parameters (including body temperature, blood eosinophils, plasma-protein, aldolase and 17-OHCS) revealed relative rhythmic oscillations of the circadian type, the ranges of which varied for for the group average between 1.4 percent (temperature) and 68 percent (17-OHCS) from the total twenty-four hour average. Negative extreme values were shown during the night hours for all cardiovascular parameters; consequently the Schneider index and the VO2 max predicted from the heart rate level during submaximal exercise had their positive peaks or best values at this time of the day. (Author)

Descriptors :   (*PERFORMANCE(HUMAN), DIURNAL VARIATIONS), (*PHYSICAL FITNESS, DIURNAL VARIATIONS), STRESS(PHYSIOLOGY), BLOOD ANALYSIS, BLOOD CHEMISTRY, CARDIOVASCULAR SYSTEM, RESPONSE(BIOLOGY), BODY TEMPERATURE, EXERCISE(PHYSIOLOGY), TOLERANCES(PHYSIOLOGY), PSYCHOMOTOR TESTS

Subject Categories : Personnel Management and Labor Relations
      Medicine and Medical Research

Distribution Statement : APPROVED FOR PUBLIC RELEASE