BackgroundRaw bioelectrical values can be used to assess physiological outcomes, though limited information is available concerning the relationships between changes in these values and changes in other variables of interest.MethodsThis investigation quantified the relationships between total and segmental changes in raw bioelectrical variables (i.e., resistance, reactance, and phase angle) and corresponding whole-body and segmental changes in independently assessed body composition. Resistance-trained females (n = 31, body mass index: 22.8 ± 2.6 kg/m2, body fat: 28 ± 6%) completed eight weeks of supervised resistance training. Before and after the intervention, body composition was assessed via dual-energy x-ray absorptiometry (GE® Lunar Prodigy), and raw bioelectrical variables were assessed via 8-point multi-frequency bioelectrical impedance analysis (Seca® mBCA 515/514) at 19 frequencies ranging from 1 to 1000 kHz.ResultsLean soft tissue of the whole body (+ 3.2% [2.1, 4.4]; mean [95% confidence interval]) and each body segment (+ 2.8 to 6.3%) increased as a result of the intervention. Group-level changes in total (− 2.4% [− 5.2, 0.3]) and segmental fat mass were not statistically significant. Significant decreases in total resistance (− 2.1% [− 3.7, − 0.6] at 50 kHz) and increases in phase angle (+ 4.2% [2.5, 5.9] at 50 kHz) were observed, with minimal changes in reactance and varying changes in segmental values. Moderate to strong negative correlations (0.63 ≤ |r| ≤ 0.83, p ≤ 0.001) were found between changes in lean soft tissue and changes in resistance for the whole body, trunk, and arms. No significant correlations were identified between changes in fat mass or bone mineral content and changes in any bioelectrical variable.ConclusionsTotal and segmental changes in resistance were associated with corresponding total and segmental changes in lean soft tissue following a resistance training intervention, while fewer associations were identified between changes in other bioelectrical parameters (i.e., reactance and phase angle) and body composition variables (e.g., fat mass and bone mineral content). Measurement frequency and body segment appeared to influence the presence and strength relationships between bioelectrical and body composition variables. These findings suggest that researchers and practitioners utilizing bioimpedance technology may benefit from examining raw resistance values to enhance detection of physiological adaptations to exercise interventions.

中文翻译：

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阻力训练干预后，总和节段生物电阻的变化与瘦软组织的全身和节段变化相关


背景原始生物电值可用于评估生理结果，尽管有关这些值的变化与其他感兴趣变量的变化之间的关系的信息有限。方法本研究量化了原始生物电变量（即电阻）的总体变化和分段变化之间的关系。 、电抗和相位角）以及独立评估的身体成分中相应的全身和节段变化。接受阻力训练的女性（n = 31，体重指数：22.8 ± 2.6 kg/m2，体脂：28 ± 6%）完成了八周的监督阻力训练。干预前后，通过双能 X 射线吸收测定法 (GE® Lunar Prodigy) 评估身体成分，并通过 8 点多频生物电阻抗分析 (Seca® mBCA 515/514) 评估原始生物电变量。 19 个频率范围从 1 到 1000 kHz。结果全身的瘦软组织（+ 3.2% [2.1, 4.4]；平均值 [95% 置信区间]）和每个身体部位（+ 2.8 到 6.3%）由于以下原因而增加的干预。总脂肪量（− 2.4% [− 5.2, 0.3]）和节段脂肪量的组级变化没有统计学意义。观察到总电阻显着下降（50 kHz 时− 2.1% [− 3.7, − 0.6]）和相角增加（50 kHz 时+ 4.2% [2.5, 5.9]），电抗变化最小，分段值。瘦软组织的变化与全身、躯干和手臂的阻力变化之间发现中度至强负相关（0.63 ≤ |r| ≤ 0.83，p ≤ 0.001）。脂肪量或骨矿物质含量的变化与任何生物电变量的变化之间没有发现显着的相关性。结论阻力的总体和分段变化与阻力训练干预后瘦软组织的相应总体和分段变化相关，而其他生物电参数（即电抗和相位角）变化与身体成分变量（例如，脂肪量和骨矿物质含量）。测量频率和身体部位似乎会影响生物电和身体成分变量之间的存在和强度关系。这些发现表明，利用生物阻抗技术的研究人员和从业者可能会受益于检查原始阻力值，以增强对运动干预的生理适应的检测。