Department of Health, Leisure, and Exercise Science, Appalachian State University, Boone, North Carolina, USA.
J Strength Cond Res. 2012 Jan;26(1):9-15. doi: 10.1519/JSC.0b013e318238ea51.
The objective of this study was to examine the validity of multifrequency direct segmental bioelectrical impedance analysis (DSM-BIA) measures to detect changes in the hydration status of wrestlers after they underwent 3% acute dehydration and a 2-hour rehydration period. Fifty-six National Collegiate Athletic Association wrestlers: (mean ± SEM); age 19.5 ± 0.2 years, height 1.73 ± 0.01 m, and body mass (BM) 82.5 ± 2.3 kg were tested in euhydrated, dehydrated (-3.5%), and 2-hour rehydration conditions using DSM-BIA to detect the changes in hydration status. The hydration status was quantified by measuring the changes in plasma osmolality (P(osm)), urine osmolality (Uosm), urine specific gravity (U(sg)), BM, and weighted segmental impedance at frequencies of 5, 20, 50, 100, and 500 kHz. Weighted segmental impedance significantly increased after a 3.5% reduction in the body weight for all the 5 frequencies evaluated, but it did not return to baseline at 2-hour rehydration. P(osm) (303 ± 0.6 mOsm·L(-1)), Uosm (617 ± 47 mOsm·L(-1)), and U(sg) (1.017 ± 0.001) all significantly increased at postdehydration and returned to baseline at 2-hour rehydration. Estimations of extracellular water were significantly different throughout the trial, but there were no significant changes in the estimations of the total body water or intracellular water. The results of this study demonstrate the potential use of DSM-BIA as a field measure to assess the hydration status of wrestlers for the purpose of minimal weight certification before the competitive season. When employing DSM-BIA to assess the hydration status, the results indicated that the changes in weighted segmental impedance at the frequencies evaluated (5, 20, 50, 100, and 500 kHz) are sensitive to acute changes in dehydration but lag behind changes in the standard physiological (plasma and urinary) markers of hydration status after a 2-hour rehydration period.
本研究的目的是检验多频直接节段生物电阻抗分析（DSM-BIA）测量值在检测摔跤运动员经历 3%急性脱水和 2 小时补液期后水合状态变化的有效性。56 名美国大学生体育协会摔跤运动员：（均值±SEM）；年龄 19.5±0.2 岁，身高 1.73±0.01 m，体重（BM）82.5±2.3 kg，在水合状态、脱水（-3.5%）和 2 小时补液条件下使用 DSM-BIA 检测水合状态变化。通过测量血浆渗透压（P(osm)）、尿渗透压（Uosm）、尿比重（U(sg)）、BM 和 5、20、50、100 和 500 kHz 频率下的加权节段阻抗的变化来量化水合状态。所有 5 个评估频率的体重减轻 3.5%后，加权节段阻抗显著增加，但在 2 小时补液后并未恢复基线。P(osm)（303±0.6 mOsm·L(-1)）、Uosm（617±47 mOsm·L(-1)）和 U(sg)（1.017±0.001）在脱水后均显著升高，并在 2 小时补液后恢复基线。细胞外液的估计值在整个试验中均有显著差异，但总水量和细胞内水的估计值无显著变化。本研究结果表明，DSM-BIA 作为一种现场测量方法，可用于评估摔跤运动员的水合状态，以便在竞技赛季前进行最小体重认证。当使用 DSM-BIA 评估水合状态时，结果表明，评估频率（5、20、50、100 和 500 kHz）下加权节段阻抗的变化对急性脱水变化敏感，但在 2 小时补液期后，对水合状态的标准生理（血浆和尿液）标志物的变化存在滞后。
