PDF(Pubmed)
Abstract：
We tested the hypothesis that women may be more at risk of becoming dehydrated during physical work in the heat in the early follicular phase (EF), compared with the late follicular (LF) and mid-luteal (ML) phases of the menstrual cycle when allowed free access to drink. Twelve healthy, eumenorrheic, unacclimated women (26 ± 5 yr) completed three trials (EF, LF, and ML phases) involving 4 h of exposure to 33.8 ± 0.8 °C, 54 ± 1% relative humidity. Each hour, participants walked on a treadmill for 30 min at a rate of metabolic heat production of 338 ± 9 W. Participants drank a cool, flavor-preferred non-caloric sport drink ad libitum. Nude body weight was measured pre- and post-exposure, and percent changes in body weight loss were interpreted as an index of changes in total body water. Total fluid intake and urine output were measured and sweat rate was estimated from changes in body mass corrected for fluid intake and urine output. Fluid intake was not different between phases (EF: 1,609 ± 919 mL; LF: 1,902 ± 799 mL; ML: 1,913 ± 671; P = 0.202). Total urine output (P = 0.543) nor sweat rate (P = 0.907) differed between phases. Percent changes in body mass were not different between phases (EF: -0.5 ± 0.9%; LF: -0.3 ± 0.9%; ML: -0.3 ± 0.7%; P = 0.417). This study demonstrates that the normal hormonal fluctuations that occur throughout the menstrual cycle do not alter fluid balance during physical work in the heat.NEW & NOTEWORTHY The effect of the menstrual cycle on fluid balance during physical work in the heat when fluids are freely available is unknown. This study demonstrates that fluid balance is not modified in women across three distinct phases of the menstrual cycle during physical work in the heat These results indicate that when women have free access to cool fluid during physical work in the heat, they respond similarly across all three phases to maintain fluid homeostasis across the menstrual cycle.
摘要：
我们测试了以下假设：在卵泡早期（EF）的高温下，女性在体力劳动期间会更脱水，与允许自由饮用的月经周期的卵泡晚期（LF）和黄体中期（ML）相比。十二健康，eumnorrhic,未适应的妇女（26±5岁）完成了三项试验（EF，LF,ML阶段），涉及暴露于33.8±0.8°C4小时，相对湿度54±1%。每小时,参与者在跑步机上行走30分钟，代谢产热速率为338±9W。口味首选无热量运动饮料。在暴露前和暴露后测量裸体体重，体重减轻的百分比变化被解释为总体内水分变化的指标。测量总液体摄入量和尿量，并根据根据液体摄入量和尿量校正的体重变化估算出汗率。不同阶段的液体摄入量没有差异（EF：1609±919mL；LF：1902±799mL；ML：1913±671；P=0.202）。各相之间的总尿量（P=0.543）和出汗率（P=0.907）不同。不同阶段之间的体重变化百分比没有差异（EF：-0.5±0.9％；LF：-0.3±0.9％；ML：-0.3±0.7％；P=0.417）。这项研究表明，在整个月经周期中发生的正常荷尔蒙波动不会在热的身体工作中有意义地改变液体调节。
