My HRV is in the "normal" range but I feel terrible. What's happening?

The "normal range" comparison is the wrong frame. HRV reference ranges are population averages drawn from groups that include men with autonomic dysfunction, men with untreated sleep apnea, men with chronic stress, and men with metabolic disease. A number that falls within a statistical average for a population with diverse health profiles is not a guarantee that your autonomic function is adequate for your biology.

The more important concept is your personal baseline, established over a sufficient period of consistent measurement under consistent conditions. A man whose personal baseline HRV has been 68 ms for two years and is now consistently 42 ms, even if 42 ms is "within the population normal range", has experienced a 38% decline that is clinically meaningful. He will feel terrible because his autonomic function has degraded substantially relative to his own previous capacity, even if the number still looks acceptable on a population chart. Your body does not know about population averages. It knows about your baseline. The feeling is data. Do not let a chart override the clinical signal your body is producing. (Thayer et al., International Journal of Cardiology, 2010)

Cardiologist's calibrated position, Solid (1) for personal baseline as the correct HRV reference frame, not population percentile.

What to do: Pull your HRV trend for the past 12 months in whatever app you use. Calculate the mean from months 1–3 and compare it to the mean from months 10–12. The percentage change, not the absolute number, is the clinical signal.

For the full picture, read Autonomic Sovereignty White Paper.