The chief limitation of heart rate-based training is that, while heart rate is a good indicator of running intensity, it's not a perfect indicator.

对于基于心率的训练，最要限制是，心率是一个好的跑步强度指标，但是不够完美。

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The basic rationale for wearing a heart rate monitor while running is that heart rate is an indicator of exercise intensity.

跑步佩戴心率表的基本原理是，心率是一个运动强度指标。

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Measurement of heart rate variability might be an important indicator for the prediction of susceptibility of motion sickness.

心率变异性检测可以作为运动病易感性重要的预测指标。

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Guidant is developing a wireless "advanced patient management" system for defibrillators, and is evaluating whether heart rate variability is a good indicator of attacks.

FORBES: The Doctor Is In