Section Sports Medicine, University of Pretoria Pretoria, South Africa.
Front Physiol. 2013 Nov 20;4:337. doi: 10.3389/fphys.2013.00337. eCollection 2013.
Quantification of cardiac autonomic activity and control via heart rate (HR) and heart rate variability (HRV) is known to provide prognostic information in clinical populations. Issues with regard to standardization and interpretation of HRV data make the use of the more easily accessible HR on its own as an indicator of autonomic cardiac control very appealing. The aim of this study was to investigate the strength of associations between an important cardio vascular health metric such as VO2max and the following: HR, HRV indicators, and HR normalized HRV indicators. A cross sectional descriptive study was done including 145 healthy volunteers aged between 18 and 22 years. HRV was quantified by time domain, frequency domain and Poincaré plot analysis. Indirect VO2max was determined using the Multistage Coopers test. The Pearson correlation coefficient was calculated to quantify the strength of the associations. Both simple linear and multiple stepwise regressions were performed to be able to discriminate between the role of the individual indicators as well as their combined association with VO2max. Only HR, RR interval, and pNN50 showed significant (p < 0.01, p < 0.01, and p = 0.03) correlations with VO2max. Stepwise multiple regression indicated that, when combining all HRV indicators the most important predictor of cardio vascular fitness as represented by VO2max, is HR. HR explains 17% of the variation, while the inclusion of HF (high frequency HRV indicator) added only an additional 3.1% to the coefficient of determination. Results also showed when testing the normalized indicators, HR explained of the largest percentage of the changes in VO2max (16.5%). Thus, HR on its own is the most important predictor of changes in an important cardiac health metric such as VO2max. These results may indicate that during investigation of exercise ability (VO2max) phenomena, quantification of HRV may not add significant value.
通过心率（HR）和心率变异性（HRV）对心脏自主活动和控制进行量化已被证明可以为临床人群提供预后信息。HRV 数据的标准化和解释问题使得单独使用更容易获得的 HR 作为自主心脏控制的指标非常有吸引力。本研究旨在探讨重要心血管健康指标（如 VO2max）与以下指标之间的关联强度：HR、HRV 指标和 HR 归一化 HRV 指标。进行了一项横断面描述性研究，纳入了 145 名年龄在 18 至 22 岁之间的健康志愿者。通过时域、频域和 Poincaré 图分析来量化 HRV。间接 VO2max 使用多阶段库珀测试确定。计算 Pearson 相关系数来量化关联的强度。进行了简单线性和逐步多元回归，以便能够区分各个指标的作用及其与 VO2max 的综合关联。只有 HR、RR 间期和 pNN50 与 VO2max 呈显著（p < 0.01、p < 0.01 和 p = 0.03）相关性。逐步多元回归表明，当结合所有 HRV 指标时，作为 VO2max 代表的心血管健康的最重要预测因子是 HR。HR 解释了 17%的变化，而包含 HF（高频 HRV 指标）仅将决定系数增加了 3.1%。结果还表明，在测试归一化指标时，HR 解释了 VO2max 变化的最大百分比（16.5%）。因此，HR 是 VO2max 等重要心脏健康指标变化的最重要预测因子。这些结果可能表明，在研究运动能力（VO2max）现象时，HRV 的量化可能不会增加显著价值。
