Tipton M J, Mekjavic I B, Eglin C M
Department of Sport and Exercise Science, University of Portsmouth, Hants, UK.
Eur J Appl Physiol. 2000 Sep;83(1):17-21. doi: 10.1007/s004210000255.
Sudden immersion in cold water initiates an inspiratory gasp response followed by uncontrollable hyperventilation and tachycardia. It is known that this response, termed the "cold shock" response, can be attenuated following repeated immersion. In the present investigation we examined how long this habituation lasts. Twelve healthy male volunteers participated in the experiment, they were divided into a control (C) group (n = 4), and a habituation (H) group (n = 8). In October, each subject undertook two 3-min head-out seated immersions into stirred water at 10 degrees C wearing swimming trunks. These immersions took place at the same time of day, with 4 days separating the two immersions. In the intervening period, the C group were not exposed to cold water, while the H group undertook six, 3-min head-out immersions in water at 15 degrees C. Two months (December), 4 months (February), 7 months (May) and 14 months (January) after their first immersion, all subjects undertook another 3-min head-out immersion in water at 10 degrees C. The H group showed a reduction in respiratory frequency (47 to 24 breaths x min(-1)), inspiratory minute volume (72.2 to 31.3 1 x min(-1)) and heart rate (128 to 109 beats x min(-1)) during the first 30 s of immersion on day 5 compared to day 1. Seven months later these responses were still significantly reduced compared to day 1. After 14 months, heart rate remained attenuated but respiratory frequency and inspiratory minute volume had returned towards pre-habituation levels. The responses of the C group during the first 30 s of immersion were not altered. Both groups showed an attenuation in the responses during the remaining 150 s of immersion following repeated immersions. It is concluded that repeated immersions in cold water result in a longlasting (7-14 months) reduction in the magnitude of the cold shock response. Less frequent immersions produced a decrease in the duration, but not the magnitude of the response.
突然浸入冷水中会引发吸气喘息反应，随后是无法控制的过度换气和心动过速。已知这种反应，即所谓的“冷休克”反应，在反复浸入后会减弱。在本研究中，我们研究了这种习惯化持续多长时间。12名健康男性志愿者参与了实验，他们被分为对照组（C组，n = 4）和习惯化组（H组，n = 8）。10月，每个受试者穿着泳裤，头部露出水面，在10摄氏度的搅拌水中进行两次3分钟的坐姿浸入。这些浸入在一天中的同一时间进行，两次浸入间隔4天。在此期间，C组未接触冷水，而H组在15摄氏度的水中进行了六次3分钟的头部露出水面浸入。在第一次浸入后的两个月（12月）、4个月（2月）、7个月（5月）和14个月（1月），所有受试者再次在10摄氏度的水中进行3分钟的头部露出水面浸入。与第1天相比，H组在第5天浸入的前30秒内呼吸频率（从47次/分钟降至24次/分钟）、吸气分钟量（从72.2升/分钟降至31.3升/分钟）和心率（从128次/分钟降至109次/分钟）均有所降低。七个月后，与第1天相比，这些反应仍显著降低。14个月后，心率仍减弱，但呼吸频率和吸气分钟量已恢复到习惯化前的水平。C组在浸入的前30秒内的反应没有改变。两组在反复浸入后的其余150秒内的反应均有所减弱。结论是，反复浸入冷水中会导致冷休克反应的幅度长期（7 - 14个月）降低。浸入频率较低会使反应持续时间缩短，但不会使其幅度降低。
