My Oura ring says my HRV is fine but I feel terrible — what's going on?

Consumer wearable HRV measurement correlates with ECG-derived RMSSD at approximately r=0.80–0.90 during sleep in most validation studies, meaning the device tracks relative changes reasonably well but can be off by 8–12 ms in absolute terms, enough to classify a physiologically suppressed reading as "within normal range" depending on your device's algorithm and your personal baseline (Haghayegh et al., J Clin Sleep Med, 2019).

The more important issue is that subjective wellbeing and HRV are not tightly coupled. HRV reflects autonomic balance, not total-body health. A man with subclinical iron deficiency, early thyroid dysfunction, or chronic sleep apnea may have "acceptable" HRV by device standards while feeling persistently fatigued. Conversely, some men habituate to chronic stress so completely that their subjective sense of wellbeing no longer tracks their objective autonomic state. The device is one signal. Your body is another. When they disagree, the right move is to investigate further, not to dismiss either signal.

Honesty Scale: Device accuracy, Promising (2) for Oura Ring overnight HRV in validation studies. The subjective-objective disconnect is an Early (3) observation in the literature.

What to do: If your HRV reads "acceptable" but you persistently feel exhausted, request a basic metabolic panel, CBC, thyroid function tests, and a home sleep study to rule out obstructive sleep apnea, which frequently causes fatigue while allowing "normal" wearable readings.

For the full picture, read Your Whoop Is Worried. Here Is What It Actually Found.