書誌： Physiology & Behavior ,2010
Physiology & Behavior 100 (2010) 340–345
Ken Tokizawa, Saki Yasuhara, Mayumi Nakamura, Yuki Uchida ,Larry I. Crawshaw, Kei Nagashima
Hypohydration caused by exercise in the heat attenuates autonomic thermoregulation such as sweating andskin blood flow in humans. In contrast, it remains unknown if behavioral thermoregulation is modulatedduring hypohydration. We assume that thermal unpleasantness could drive the behavioral response, andwould also be modulated during hypohydration. Nine healthy young men participated in the present study.Body and skin temperatures were monitored. Ratings of thermal sensation and pleasantness wereconducted. After ∼ 45 min rest at 27 °C, they performed 50-min cycling exercise, which was at the level of40% of heart rate range at 35 °C (hypohydration trial) or at the level of 10% of heart rate range at 23 °C(control trial), respectively. Subjects returned to the rest at 27 °C, and the ambient temperature was thenchanged from 22 to 38 °C. Body weight decreased by 0.9 ±0.1% immediately after exercise in thehypohydration trial and 0.3 ±0.1% in the control trial. In the cold, no significant difference in thermalsensation or pleasantness was observed between trials. There was no significant difference in thermalpleasantness between trials in the heat, although thermal sensation in the heat (32.5–36 °C) wassignificantly lower in the hypohydration trial than in the control trial. In addition, laser Doppler flow ofthe skin and sweat rate were attenuated in the heat in the hypohydration trial. These results may indicatethat mild hypohydration after exercise in the heat has no influence on behavioral responses to the heat.