Mitchell J B, McFarlin B K, Dugas J P
Exercise Physiology Laboratory, Texas Christian University, Fort Worth, TX 76129, USA.
Int J Sports Med. 2003 Feb;24(2):118-24. doi: 10.1055/s-2003-38203.
The purpose of this study was to determine the effect of pre-exercise cooling on high intensity, moderate duration running performance and thermoregulatory responses in a hot environment (38 degrees C, 40 %RH). On separate days, 11 male subjects completed two treadmill runs to exhaustion at 100% of maximal aerobic power with (CL) and without (CT) pre-exercise cooling. Cooling consisted of 20 min of standing rest in a 22 degrees C environment with fan cooling (4.0 m x sec -1) and water spraying (50 ml x min -1) applied to both anterior and posterior body surfaces. Core temperature (T(c)) was determined with an esophageal T(es) probe, and skin temperatures (T(sk)) were measured using surface thermistors positioned at four sites. Finger prick blood samples were taken before and after exercise for the determination of blood lactate. Heart rates and ratings of thermal sensations and comfort were also recorded. Time to exhaustion was significantly shorter in the CL condition (368.9 +/- 56.2) compared to the CT condition (398.8 +/- 55.5 sec). Peak T(es) (37.51 +/- 0.57 vs. 38.56 +/- 0.30 degrees C for CL and CT, respectively), T(sk) (34.18 +/- 1.22 vs. 36.15 +/- 0.70 degrees C for CL and CT, respectively), rates of heat gain (0.20 +/- 0.05 vs. 0.28 +/- 0.05 degrees C x min -1 for CL and CT, respectively), and net heat storage (238.4 +/- 109.6 vs. 531.9 +/- 78.3 kJ for CL and CT, respectively) were all lower in the CL compared to CT throughout the treadmill runs. There were no differences in lactate accumulation between the two conditions. Based on these data, it can be concluded that pre-exercise cooling influences thermoregulatory responses during high intensity, moderate duration exercise; however, performance is impaired compared to a control trial in which no cooling procedures were employed.
本研究的目的是确定运动前降温对在炎热环境（38摄氏度，40%相对湿度）下高强度、中等时长跑步表现及体温调节反应的影响。在不同日期，11名男性受试者分别在有（CL）和无（CT）运动前降温的情况下，以最大有氧功率的100%在跑步机上跑步直至力竭。降温措施包括在22摄氏度环境中站立休息20分钟，同时使用风扇（风速4.0米/秒）和向身体前后表面喷水（50毫升/分钟）。用食管温度探头测定核心温度（T(c)），并使用置于四个部位的表面热敏电阻测量皮肤温度（T(sk)）。在运动前后采集手指针刺血样以测定血乳酸。还记录心率、热感觉评分和舒适度评分。与CT组（398.8±55.5秒）相比，CL组（368.9±56.2）的力竭时间显著缩短。在整个跑步机跑步过程中，CL组的峰值食管温度（分别为37.51±0.57摄氏度和38.56±0.30摄氏度）、皮肤温度（分别为34.18±1.22摄氏度和36.15±0.70摄氏度）、热量增加速率（分别为0.20±0.05摄氏度/分钟和0.28±0.05摄氏度/分钟）以及净热量储存（分别为238.4±109.6千焦和531.9±78.3千焦）均低于CT组。两种情况下乳酸积累无差异。基于这些数据，可以得出结论，运动前降温会影响高强度、中等时长运动期间的体温调节反应；然而，与未采用降温程序的对照试验相比，运动表现会受到损害。
