Thermoregulatory responses of pre-, mid-, and late-pubertal boys to exercise in dry heat.
Thermoregulatory responses of pre-, mid-, and late-pubertal boys to exercise in dry heat.
复制标题
青春期前、中期和晚期男孩对干热运动的体温调节反应。
DOI：
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发表时间：
1992
影响因子：
4.1
通讯作者：
J. Macdougall
中科院分区：
文献类型：
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作者：
Bareket Falk;Oded Bar;J. Macdougall
据报道，在炎热的气候中锻炼时，儿童的体温调节能力不如成人。从儿童样反应到成人样反应的转变很可能发生在青春期。为了评估体温调节反应和身体成熟之间的关联，三组青春期男孩在50%VO2max（三个20分钟的回合，休息10分钟），在气候室（42摄氏度，20%相对湿度）。根据坦纳分期（阴毛），10例被分类为青春期前（PP），13例为青春期中期（MP），8例为青春期晚期（LP）。测量包括直肠和皮肤温度（Tre、Tsk）、心率（HR）、出汗率（SR）、耗氧量（VO 2）和前臂血流量（FBF）。Tre、Tsk和HR随时间增加而增加，组间无显著差异。各组的相对VO 2（ml O2.kg-1）相似。PP的FBF始终高于LP。尽管SR较高，（PP = 4.9 +/- 0.2，MP = 5.7 +/- 0.3，LP = 6.6 +/- 0.4 ml.min-1.m-2）（平均值+/- SEM）LP与PP相比，（PP = 5.5 +/- 0.4，MP = 5.3 +/- 0.4，LP = 6.8 +/- 0.3，kJ·h-1·kg-1）也显著高于LP组。8例LP中有3例由于Tre高而未完成会话，而10例PP中有2例无法完成会话，即使生理热应变不高。结果表明，在炎热干燥的气候中，从儿童般的体温调节有效性转变为成人般的体温调节有效性可能发生在稍晚的阶段，但不是在青春期。
During exercise in a hot climate, children have been reported to have a less effective temperature regulation capability, compared with adults. It is likely that the transition from a child-like to an adult-like response occurs during puberty. To assess the association between the thermoregulatory response and physical maturation, three groups of circum-pubertal boys cycled at 50% VO2max (three 20-min bouts with 10-min rests), in a climatic chamber (42 degrees C, 20% relative humidity). Based on Tanner staging (pubic hair), 10 were classified as prepubertal (PP), 13 as midpubertal (MP), and eight as late pubertal (LP). Measurements included rectal and skin temperatures (Tre, Tsk), heart rate (HR), sweating rate (SR), oxygen consumption (VO2), and forearm blood flow (FBF). Tre, Tsk, and HR increased with time, with no significant difference among groups. Relative VO2 (ml O2.kg-1) was similar among groups. FBF was consistently higher in PP compared with LP. In spite of the higher SR (PP = 4.9 +/- 0.2, MP = 5.7 +/- 0.3, LP = 6.6 +/- 0.4 ml.min-1.m-2) (mean +/- SEM) among LP compared with PP, the rate of heat storage (PP = 5.5 +/- 0.4, MP = 5.3 +/- 0.4, LP = 6.8 +/- 0.3, kJ.h-1.kg-1) was also significantly higher among those in the LP group. Three of eight LP did not complete the session due to high Tre, while two of the 10 PP were unable to complete the session even though the physiologic heat strain was not high. The results suggest that the transition from a child-like to an adult-like thermoregulatory effectiveness in a hot, dry climate may occur at a somewhat later stage, but not during puberty.