I would add a point. HRV is modified durably by exercise, and that induced modification has a duration of several days. We have a typical allostasis state with the equilibrium point displaced for several days if the exercice is intense enough. Thus, the measurements from week to week should not be at random but should be performed following days with similar exercise activity to be comparable from week to week. Following this schedule would allow to reducce the measurement density as low as once a week. See Chalencon et al. Plos One 2012 and Eur J Appl Physiol 2015).
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I would add a point. HRV is modified durably by exercise, and that induced modification has a duration of several days. We have a typical allostasis state with the equilibrium point displaced for several days if the exercice is intense enough. Thus, the measurements from week to week should not be at random but should be performed following days with similar exercise activity to be comparable from week to week. Following this schedule would allow to reducce the measurement density as low as once a week. See Chalencon et al. Plos One 2012 and Eur J Appl Physiol 2015).
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