Department of Neurosciences, Biomedicine and Movement Sciences, University of Verona, Verona, ITALY.
Department of Movement and Sports Sciences, Ghent University, Watersportlaan2, Ghent, BELGIUM.
Med Sci Sports Exerc. 2022 Apr 1;54(4):655-664. doi: 10.1249/MSS.0000000000002835.
We tested the hypothesis that a slow component of HR (i.e., scHR) occurs in all intensity domains, greater than the slow component of oxygen uptake (scV˙O2), and we developed an equation to predict it across exercise intensities.
Eighteen healthy, postmenopausal women (54 ± 4 yr) performed on a cycle ergometer: i) a ramp incremental test for thresholds and V˙O2max detection; ii) 30-min constant work exercise at 40%, 50%, 60%, 70%, and 80% V˙O2max for the measurement of scHR, scV˙O2, stroke volume, and body temperature (T°). scHR and scV˙O2 were compared by two-way repeated-measures ANOVA (intensity and variable). Pearson correlation was calculated between the slow component of all variables, relative intensity, and domain. scHR (in beats per minute) was predicted with a linear model based on exercise intensity relative to the respiratory compensation point (RCP).
A positive scHR was present in all domains, twice the size of scV̇O2 (P < 0.001), and significantly correlated with the slow components of V̇O2 (r2 = 0.46), T° (r2 = 0.52), and relative intensity (r2 = 0.66). A linear equation accurately predicts scHR based on %RCP (r2 = 0.66, SEE = 0.15).
A mismatch exists between the slow components of HR and metabolic intensity. Whenever exercise is prescribed based on HR, target values should be adjusted over time to grant that the desired metabolic stimulus is maintained throughout the exercise session.
我们检验了这样一个假设，即在所有的强度范围内都会出现心率的缓慢变化成分（即 scHR），而且它大于摄氧量的缓慢变化成分（scV˙O2），我们开发了一个方程来预测它在运动强度范围内的变化。
18 名健康的绝经后妇女（54 ± 4 岁）在自行车测力计上进行了以下测试：i）斜坡递增测试以确定阈值和 V˙O2max 检测；ii）30 分钟的 40%、50%、60%、70%和 80%V˙O2max 恒功运动，以测量 scHR、scV˙O2、心输出量和体温（T°）。通过双因素重复测量方差分析（强度和变量）比较 scHR 和 scV˙O2。计算了所有变量、相对强度和域之间的缓慢变化成分的 Pearson 相关性。根据运动强度与呼吸补偿点（RCP）的相对关系，使用线性模型预测 scHR（以每分钟节拍数表示）。
在所有的运动强度范围内都存在正的 scHR，它是 scV̇O2 的两倍（P < 0.001），并且与 V̇O2 的缓慢变化成分显著相关（r2 = 0.46），T°（r2 = 0.52）和相对强度（r2 = 0.66）。一个线性方程可以根据 %RCP 准确地预测 scHR（r2 = 0.66，SEE = 0.15）。
心率和代谢强度的缓慢变化成分之间存在不匹配。无论何时根据心率来制定运动处方，都应该随着时间的推移调整目标值，以确保在整个运动过程中保持所需的代谢刺激。
