||The purpose of this study was to examine the effects of body cooling with water intake during moderate exercise on thermoregulatory responses. Eight healthy male subjects pedalled a cycle ergometer at... the work rate of 55% VO2max for 60 minutes, under the temperate condition : ambient temperature, 24°C and room humidity, 50％. The subjects were cooled by means of cold packs (147cm2) for 5 minutes. During exercise, the cooling was performed every 15 minutes through the following procedures : 1) a 5-minute's cooling of forehead skin after the initial 16 minutes of exercise, 2) a 5-minute's cooling of lumbodorsal skin after 31 minutes of exercise, 3) a 5-minute's cooling both forehead and lumbodorsal skin after 46 minutes of exercise. For the recovery period, another 5-minute cooling was given to both forehead and lumbodorsal skin, starting from 6-minutes after the exercise was over. Each subject was given mineral water of 1.6 ml/kg (about 100 ml) at the start of each body cooling. Rectal temperature, ear canal temperature, skin temperature, heart rate (HR) and sweat rate were measured. Water intake during exercise suggested the delay of the increase of body and skin temperatures. Body cooling during exercise showed the restraint of the increase of body temperature and heat storage. Body cooling during exercise is effective for the restraint of the increase of HR compared with that during water intake. Total weight loss during exercise was equivalent to 1.13% before exercise. Then, water intake and body cooling had no an effect. No noticeable relationship was observed between water intake, body cooling and sweat rate during exercise. These results suggested that body cooling affects the thermoregulatory responses compared with water intake during exercise.
本研究は，運動時の身体冷却と水分摂取が体温調節反応に及ぼす影響を検討する目的で，健康な男子大学生8名を対象に，常温常湿環境下で自転車エルゴメータを用いて，55.4±4.2% VO2maxに相当する中等度の運動を60分間負荷した。運動時および回復期に身体冷却と水分摂取を同時処置し，深部体温，皮膚温，心拍数および発汗応答について測定した。その結果を要約すると次のとおりである。 1．運動時の水分摂取は，身体冷却だけの場合に比較して，深部体温および皮膚温の上昇を約2分間遅延させる効果が示唆された。身体冷却は，体温上昇や体熱量を抑制する傾向が認められた。 2．身体冷却は，水分摂取より心拍数増加の抑制が大きかった。 3．体重減少量は，1.13%に相当し，水分摂取および身体冷却による影響は認められなかった。 4．水分摂取および身体冷却と発汗量との間に顕著な差は認められなかった。 本研究から，水分摂取より身体冷却が運動時の体温調節反応に及ぼす影響が大きいことが示唆された。続きを見る