Havenith G, Luttikholt V G, Vrijkotte T G
TNO Human Factors Research Institute, Soesterberg, The Netherlands.
Eur J Appl Physiol Occup Physiol. 1995;70(3):270-9. doi: 10.1007/BF00238575.
The present study was designed to determine the relative importance of individual characteristics such as maximal oxygen uptake (VO2max), adiposity, DuBois body surface area (AD), surface to mass ratio (AD: mass) and body mass, for the individual's reaction to humid heat stress. For this purpose 27 subjects (19 men, 8 women), with heterogeneous characteristics (VO2max 1.86-5.28 1.min-1; fat% 8.0%-31.9%; mass 49.8-102.1 kg; AD 1.52-2.33 m2) first rested (30 min) and then exercised (60 W for 1 h) on a cycle ergometer in a warm humid climate (35 degrees C, 80% relative humidity). Their physiological responses at the end of exercise were analysed to assess their relationship with individual characteristics using a stepwise multiple regression technique. Dependent variables (with ranges) included final values of rectal temperature (Tre 37.5-39.0 degrees C), mean skin temperature (Tsk 35.7-37.5 degrees C), body heat storage (S 3.2-8.1 J.g-1), heart rate (HR 100-172 beat.min-1), sweat loss (397-1403 g), mean arterial blood pressure (BPa, 68-96 mmHg), forearm blood flow (FBF, 10.1-33.9 ml.100ml-1.min-1) and forearm vascular conductance (FVC = FBF/BPa, 0.11-0.49 ml.100ml-1.min-1.mmHg-1). The Tre, Tsk and S were (34%-65%) determined in the main by VO2max or by exercise intensity expressed as a percentage of VO2max (% VO2max). For Tre, AD: mass ratio also contributed to the variance explained, with about half the effect of VO2max. For Tsk, fat% contributed to the variance explained with about two-third the effect of VO2max. Total body sweat loss was highly dependent (50%) on body size (AD or mass) with regular activity level having a quarter of the effect of body size on sweat loss. The HR, similar to Tre, was determined by VO2max (48%-51%), with less than half the effect of AD or AD:mass (20%). Other circulatory parameters (FBF, BPa, FVC) showed little relationship with individual characteristics (< 36% of variance explained). In general, the higher the VO2max and/or the bigger the subject, the lower the heat strain observed. The widely accepted concept, that body core temperature is determined by exercise intensity expressed as % VO2max and sweat loss by absolute heat load, was only partially supported by the results. For both variables, other individual characteristics were also shown to contribute.
本研究旨在确定个体特征（如最大摄氧量（VO2max）、肥胖程度、杜波依斯体表面积（AD）、表面积与质量比（AD:质量）和体重）对个体在湿热应激下反应的相对重要性。为此，选取了27名特征各异的受试者（19名男性，8名女性）（VO2max为1.86 - 5.28 l·min-1；脂肪百分比为8.0% - 31.9%；体重为49.8 - 102.1 kg；AD为1.52 - 2.33 m2），先在温暖潮湿的环境（35摄氏度，相对湿度80%）中休息（30分钟），然后在功率自行车上以60瓦的功率运动1小时。运动结束时分析他们的生理反应，采用逐步多元回归技术评估这些反应与个体特征之间的关系。因变量（范围）包括直肠温度（Tre为37.5 - 39.0摄氏度）、平均皮肤温度（Tsk为35.7 - 37.5摄氏度）、身体蓄热（S为3.2 - 8.1 J·g-1）、心率（HR为100 - 172次·min-1）、汗液流失量（397 - 1403克）、平均动脉血压（BPa，68 - 96 mmHg）、前臂血流量（FBF，10.1 - 33.9 ml·100ml-1·min-1）和前臂血管传导率（FVC = FBF/BPa，0.11 - 0.49 ml·100ml-1·min-1·mmHg-1）。Tre、Tsk和S主要（34% - 65%）由VO2max或表示为VO2max百分比（%VO2max）的运动强度决定。对于Tre，AD:质量比也对所解释的方差有贡献，其影响约为VO2max的一半。对于Tsk，脂肪百分比对所解释的方差有贡献，其影响约为VO2max的三分之二。总体汗液流失高度依赖（50%）于身体大小（AD或体重），在活动水平一定的情况下，身体大小对汗液流失的影响是活动水平的四倍。HR与Tre相似，由VO2max决定（48% -
