Initial Fine Control Mechanism of Sweating in Well-Trained Athletes

在常温(23ﾟC)、相对湿度为60%的条件下，测定了有无长期有规律的体力活动(运动员8年以上，非运动员至少2年)的受试者在中等强度的自行车运动(80W，30min)中胸部和大腿的局部出汗率和排汗频率。采用电容式湿度计-通气胶囊法记录受试者的出汗率和排汗规律。利用MacLab硬件单元(MacLab/8e)的软件(箔条v3.5)中的微分函数从原始出汗波中提取出汗差分波。运动员和非运动员的身体特征除最大摄氧量外，其余各项指标均无显著差异。运动员的MSW有降低的趋势。与非运动员相比，运动员的MSW随FSW的增加而升高的幅度明显减小，FSW的控制率也显著降低。运动期运动员的平均每分钟排汗量(FSW)显著低于非运动员。运动员FSW与平均体温(MTH)的回归系数显著大于非运动员。运动开始后，平均皮肤温度(MTS)会暂时下降，这在运动员中不太明显。运动结束时MTS在运动员中显著升高，而在非运动员中无显著变化。结果表明，长期的运动训练改善了循环对皮肤的热传递，增强了对排汗的神经控制，进而有降低出汗率的趋势。FSW与平均体温、局部出汗率和FSW之间的相关系数在差分波中大于原始波。

Local sweat rates (Msw) at the chest and thigh and the frequency of sweat expulsions (Fsw) were determined in human subjects with and without long-term regular physical activities (athlctes : for more than 8 years, non-athletes at least for the past 2 years) during moderate bicycle exercise (80 W for 30 min) at ambient thermoneutrality (23ﾟC) and 60% relative humidity. The sweat rate and sweat expulsion patterns were recorded by a capacitance hygrometer-ventilated capsule method. The differential waves of sweat expulsion were derived from the original sweating waves by using the differential function in software (Chaff v3.5) with the MacLab hardware unit (MacLab/8e).There was no significant difference in the physical characteristics between athletes and non-athletes, except for VO2max.There was a tendency of Msw to be lower in athletes. The rise of Msw with increasing Fsw was significantly less steep and Fsw was also controlled at a significantly lower rate in athletes as compared to non-athletes. The average Fsw (sweat expulsions per min) during exercise period was significantly lower in athletes than in non-athletes. A regression coefficient between Fsw and mean body temperature (mTh) for athletes was significantly larger than the coefficient for non-athletes. The start of exercise was followed by a temporary decrease in mean skin temperature (mTs) which was less distinct in athletes. The rise in mTs at thc end of exercise was significant in athletes but not in non-athletes.The results indicate that long-term physical training leads to improved circulatory heat transfer to the skin and to a more graded nervous control of sweat expulsion and, further, tends to reduce the rate of sweating.The correlation coefficients in the relationships between Fsw and mean body temperature, local sweat rate and Fsw were larger in the differential waves than in the original waves.