PURPOSE Accurate quantification and monitoring of exercise "dose", described by oxygen consumption (VO2), is necessary for exercise prescription and individualization. However, due to the complexity and elevated cost of direct, gold-standard methods, this is rarely done outside research laboratories. Heart rate-index (HRindex) is a new simple method to estimate VO2 in healthy and clinical populations. We tested the performance of HRindex to estimate VO2 in diabetic patients during aerobic (AT) and isotonic training (IT). METHODS Data from 12 males (age: 64 ± 5 years; BMI: 26 ± 12) with type 2 diabetes were analysed. VO2 and heart rate were measured during one AT and one IT session. Furthermore, VO2 was indirectly estimated based on HRindex. Then, the correspondence between measured and estimated VO2 was evaluated by two-way RM-ANOVA, correlation and Bland-Altman analysis. RESULTS Estimated average VO2 values during AT (1292 ± 366 ml/min) were not different from (p = 0.243) and highly correlated with (r = 0.87, p < 0.001) the measured values (1369 ± 417 ml/min), with a small bias and imprecision. Conversely during IT, HRindex overestimated VO2 compared to the actual measures (1048 ± 404 vs 667 ± 230 ml/min, p ≤ 0.001) and only a moderate correlation was found between values (r = 0.43, p ≤ 0.001), with a large bias and imprecision. CONCLUSION VO2 of aerobic exercises can be accurately estimated in diabetes patients using HRindex. During isotonic exercise, this method is not recommended for monitoring metabolic intensity due to large overestimation and imprecision. In aerobic exercise, HRindex offers a simple and valid alternative to the direct VO2 determination and may favour the applicability of time-resolved measures of exercise "dose".

中文翻译：

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监测糖尿病患者的运动强度：“心率指数”在有氧运动和阻力训练中用于估计耗氧量的适用性。

目的对运动“剂量”进行准确的定量和监测，以耗氧量（VO2）进行描述，对于运动处方和个体化是必要的。但是，由于直接的金标准方法的复杂性和成本的上升，很少在研究实验室之外进行。心率指数（HRindex）是估算健康和临床人群中VO2的一种新的简单方法。我们测试了HRindex的性能，以评估有氧（AT）和等渗训练（IT）期间糖尿病患者的VO2。方法分析12位2型糖尿病男性的数据（年龄：64±5岁； BMI：26±12）。在一次AT和一次IT会话中测量了VO2和心率。此外，VO2是根据HRindex间接估算的。然后，通过双向RM-ANOVA评估测得的和估算的VO2之间的对应关系，相关性和Bland-Altman分析。结果AT期间的平均VO2估计值（1292±366 ml / min）与（p = 0.243）并无差异，并且与（r = 0.87，p <0.001）的测量值（1369±417 ml / min）高度相关，偏见和不精确。相反，在IT期间，HRindex与实际测量值相比高估了VO2（1048±404对667±230 ml / min，p≤0.001），并且值之间仅存在适度的相关性（r = 0.43，p≤0.001），具有较大的相关性。偏见和不精确。结论使用HRindex可以准确估计糖尿病患者的有氧运动VO2。在等渗运动中，由于高估和不精确，不建议使用此方法监测代谢强度。在有氧运动中