热环境下运动和劳动时出汗丢失水份和无机元素的研究

研究表明,在热环境下运动和劳动,大量排汗是体内无机元素钾、钠、钙、镁等丢失的重要原因,应采取合理的补充措施,否则易导致机体内稳态失调与一系列功能障碍。

SWEAT LOSSES OF WATER AND INORGANIC ELEMENTS DURING EXERCISE AND WORK IN HOT ENVIRONMENT

The amount of sweat was studied in 18 healthy male athletes and 9 male workers during exerciseand work in hot environment (DB 27.7--39.2°C, RH 35.5%--66.2%) in summer. Meanwhile, Zn, Cu,Fe, K, Na, Ca and Mg were measured by atomic absorption spectrometry in sweat samples collectedby the arm-bag and leg-bag technique. The sweating rates, in ml/min, were 21.7, 18.3 and 8.2 withsignificant difference from each other among the three groups for VO_2 max exercise load test, longdistance run and work in hot environment, respectively. It showed that the sweating rates wereclosely related to exerise intensity. In sweat samples during the first half of exercise, the concentra-tions of Cu, Fe, K, Na and Mg were significantly higher than those of the second half. Furthermore,the concentrations of Zn, Cu, K, Na and Mg in sweat samples from arm skin were significantly greater than those from leg skin. Sweat losses of trace elements, in mg/L, were; Zn, 0.975--1.230; Cu,0.465--0.974; and Fe, 0.384--0.928, respectively. The losses of Zn, Cu, and Fe were about 26%-33%,37%-76% and 13%-31% of thier RDA in the estimated 4 liter of sweat per day. Thus, the heavysweat losses of inorganic elements should be noticed in a hot environment.