Nielsen B, Kassow K, Aschengreen F E
August Krogh Institute, University of Copenhagen, Denmark.
Eur J Appl Physiol Occup Physiol. 1988;58(1-2):189-96. doi: 10.1007/BF00636625.
10 male subjects, dressed only in white shorts, exercised for 120 min at 92 W on a bicycle ergometer suspended in a balance. For the first 60 min they were exposed to the sun, from 60.-90. min they were shaded, and from 90.-120. min again exposed to the sun. In 10 experiments they faced the sun, in 10 others their backs were exposed. The values (in W) in the heat balance equation M - W +/- C +/- R +/- E +/- L +/- S = 0 were measured by partitional calorimetry: M metabolic rate, W external work rate, C convective heat loss, R short and long wave radiation exchange, E evaporative sweat loss, L pulmonary evaporative loss, and S rate of heat storage. Means of the measured values (W) are shown below. R in the heat balance equation equals the radiative short wave (Rgs) and long wave (Rgl) heat gains minus the radiative long wave heat loss (Rll). (table; see text) The direct gain from solar radiation is approximately 100 W. In the shade period the reduction in radiant heat gain is compensated for by the decreased evaporation of sweat.
10名男性受试者仅穿着白色短裤，在悬挂于天平上的自行车测力计上以92瓦的功率锻炼120分钟。在最初的60分钟里，他们暴露在阳光下，从60至90分钟处于阴凉处，从90至120分钟再次暴露在阳光下。在10次实验中他们面向太阳，在另外10次实验中他们的背部暴露在外。通过分区量热法测量热平衡方程M - W ± C ± R ± E ± L ± S = 0中的各项数值（单位为瓦）：M为代谢率，W为外部做功速率，C为对流热损失，R为短波和长波辐射交换，E为汗液蒸发损失，L为肺部蒸发损失，S为蓄热速率。测量值（单位为瓦）的平均值如下所示。热平衡方程中的R等于辐射短波（Rgs）和长波（Rgl）的热量增益减去辐射长波热损失（Rll）。（表格；见正文）太阳辐射的直接增益约为100瓦。在阴凉期，辐射热增益的减少通过汗液蒸发的减少得到补偿。
