No effect of 5% hypohydration on running economy of competitive runners at 23°C
No effect of 5% hypohydration on running economy of competitive runners at 23°C
复制标题
DOI：
10.1249/01.mss.0000230123.68394.ff
复制
发表时间：
2006-10-01
期刊：
影响因子：
--
通讯作者：
Maresh, Carl M.
中科院分区：
文献类型：
--
作者：
Armstrong, Lawrence E.;Whittlesey, Michael J.;Maresh, Carl M.
目的：尽管跑步经济性（RE）被认为是成功耐力表现的一个组成部分，并受到许多因素的影响，但人们对身体水分流失对RE的影响知之甚少。本研究探讨了低水合（HY）对RE和相关生理反应的影响。方法：10名训练有素的大学生长跑运动员(平均+/- SD，年龄20 +/- 3岁，身高178.5 +/- 6.3 cm，体重66.7 +/- 5.4 kg, Vo(2max), 66.5 +/- 4.1 mL(.)kg（-1)min(-1)）分别在不同的天参加了4项实验，两次处于脱水状态（EU），两次处于HY状态（24小时内体重损失- 5.5%和-5.7%）。在每个水合水平下，受试者每天进行一次10分钟的跑步机跑步（23℃环境），在70% VO2max （EU 70%或HY 70%）或85% VO2max （EU 85%或HY 85%）的随机重复测量设计中。测量了心肺、代谢、热、激素和知觉变量。结果：RE (EU 70%, 46.3 +/- 3.2; HY 70%, 47.2 +/- 3.8; EU 85%, 58.6 +/- 2.8; HY 85%, 58.9 +/- 4.1 mL(.)kg（-1.)min(-1)）、运动后血浆乳酸浓度（EU 70%, 1.9 +/- 0.6; HY 70%, 1.8 +/- 0.6; EU 85%, 6.5 +/- 3.5; HY 85%, 6.4 +/- 3.5 mmol(.)）无治疗间差异。L(-1))，或感知运动的等级。HY导致心率（HR）、直肠温度和血浆去甲肾上腺素浓度（NE）升高（P < 0.05 ~ 0.001），同时心输出量、搏量和呼吸交换比降低。结论：HY没有改变耐力运动员在70和85% VO2max条件下10分钟运动时的RE和乳酸积累。这些结果表明，在23℃环境下，HY对RE没有影响，但增加了生理应变。
Purpose: Although running economy (RE) is recognized as an integral component of successful endurance performance and is affected by numerous factors, little is known about the influence of body water loss on RE. This investigation examined the effects of hypohydration (HY) on RE and associated physiological responses. Methods: Ten highly trained collegiate distance runners (mean +/- SD; age, 20 +/- 3 yr; height, 178.5 +/- 6.3 cm; body mass, 66.7 +/- 5.4 kg; Vo(2max), 66.5 +/- 4.1 mL(.)kg(-1.)min(-1)) participated in four experiments on separate days, twice in a euhydrated (EU) and twice in a HY state (-5.5 and -5.7% body mass loss achieved during 24 h). At each hydration level, subjects performed one 10-min treadmill run per day (23 degrees C environment), at either 70% VO2max (EU 70% or HY 70%) or 85% VO2max (EU 85% or HY 85%) in a randomized, repeated-measures design. Cardiopulmonary, metabolic, thermal, hormonal, and perceptual variables were measured. Results: No between-treatment differences existed for RE (EU 70%, 46.3 +/- 3.2; HY 70%, 47.2 +/- 3.8; EU 85%, 58.6 +/- 2.8; HY 85%, 58.9 +/- 4.1 mL(.)kg(-1.)min(-1)), postexercise plasma lactate concentration (EU 70%, 1.9 +/- 0.6; HY 70%, 1.8 +/- 0.6; EU 85%, 6.5 +/- 3.5; HY 85%, 6.4 +/- 3.5 mmol(.)L(-1)), or rating of perceived exertion. HY resulted in a greater (P < 0.05 to 0.001) heart rate (HR), rectal temperature, and plasma norepinephrine concentration (NE), concurrent with reduced cardiac output, stroke volume, and respiratory exchange ratio. Conclusion: HY did not alter the RE or lactate accumulation of endurance athletes during 10 min of exercise at 70 and 85% VO2max. These findings indicate that HY had no effect on RE, but that it increased physiological strain in a 23 degrees C environment.