暑熱下の運動開始直後の体温調節反応 THERMOREGULATORY RESPONSES OF THE INITIAL STAGE OF BICYCLING IN A HEAT ENVIRONMENT

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Author(s)

    • 鳥井 正史 TORII MASAFUMI
    • 熊本大学・体質医学研究所・生理学研究部 <I>Department of Physiology, Institute of Constitutional Medicine, Kumamoto University</I>
    • 山崎 昌廣 YAMASAKI MASAHIRO
    • 熊本大学・体質医学研究所・生理学研究部 <I>Department of Physiology, Institute of Constitutional Medicine, Kumamoto University</I>
    • 佐々木 隆 SASAKI TAKASHI
    • 熊本大学・体質医学研究所・生理学研究部 <I>Department of Physiology, Institute of Constitutional Medicine, Kumamoto University</I>

Abstract

The purpose of this study is to determine the progress of whole body sweating rate (SR) in the initial stage of moderate work in two hot environments, and to relate the SR to the body temperature attained.<BR>Four healthy males, 28 to 31 years of age, performed leg exercise of 40% VO<SUB>2</SUB>max with a Monark bicycle ergometer set up on a platform scale (Potter bed balance) . All the experiments were carried out in a climatic chamber at ambient temperature (<I>T</I>a) of 30°C or 40°C (relative humidity, 45%) in winter season following body heating for 30 min at a room temperature of 30°C. Skin sweating was monitored by the bed balance with automatic weight change indicator throughout the experimental period. Rectal (<I>T</I>re) and 7 skin temperatures were measured every minute by a thermistor and thermocouples, respectively. Oxygen consumption was determined before and during the work by the Douglas bag method. Heart rate was recorded by electrocardiography throughout the experiment.<BR>At <I>T</I>a 40°C, the SR increased as soon as the work started, whereas at <I>T</I>a 30°C it took a few minutes. The mean SR during the work at <I>T</I>a 40°C was significantly higher than that at <I>T</I>a 30°C. The level of mean skin temperature (<I>T</I>sk) was higher at <I>T</I>a 40°C (35°C) than <I>T</I>a 30°C (33°C), and <I>T</I>re was approximately 37.3°C at <I>T</I>a 30°C and 40°C. The changes in the <I>T</I>re and <I>T</I>sk were similar in two different conditions. The negative correlations were found between the SR and the <I>T</I>sk during the work. The regression line was significantly different at <I>T</I>a 30°C and 40°C. The <I>T</I>sk decreased in proportion to increase of the SR. Moreover, there was a good correlation between the SR and heart rate during the work in both environments. Heat production stood at the same level in two different thermal conditions.<BR>The present study suggests that the body core temperature in working men is maintained at least constant level, since the evaporation in the initial stage of the work is largely stimulated, and the reduction of skin temperature may be caused by other factors than the evaporation.

Journal

  • Japanese Journal of Physical Fitness and Sports Medicine

    Japanese Journal of Physical Fitness and Sports Medicine 33(2), 98-104, 1984

    The Japanese Society of Physical Fitness and Sport Medicine

Cited by:  2

Codes

  • NII Article ID (NAID)
    110001927933
  • NII NACSIS-CAT ID (NCID)
    AN00137986
  • Text Lang
    UNK
  • Article Type
    Journal Article
  • ISSN
    0039-906X
  • NDL Article ID
    3012419
  • NDL Source Classification
    SC741(運動医学)
  • NDL Source Classification
    ZF21(教育--体育)
  • NDL Call No.
    Z7-301
  • Data Source
    CJPref  NDL  NII-ELS  IR  J-STAGE 
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