Hello Garmin team and fellow users,
I’m a Forerunner 255 user on firmware version 23.20, and I’ve observed a troubling pattern: my overnight HRV has dropped significantly — suggesting infection or physiological stress — yet my resting heart rate (RHR) remains completely unchanged.
From both personal experience and physiological norms, an actual infection or systemic strain would typically present with **↓ HRV + ↑ RHR** (usually +10–15 bpm). The fact that only HRV changes, while RHR stays stable, is inconsistent with expected bodily responses.
This appears to be a **measurement anomaly**, possibly due to:
- Optical sensor artifacts (e.g. poor contact, movement)
- Algorithm changes in fw 23.20 altering HRV calibration
- Lack of internal cross-check between HRV and RHR
Other users have reported similar HRV-related issues post-update (↓ HRV with normal activity levels) .
**I therefore ask:**
1. Could Garmin investigate whether fw 23.20’s HRV calculation might be miscalibrated when RHR remains stable?
2. Consider implementing an internal **HRV–RHR consistency check**—if HRV drops without RHR change, flag it as potentially unreliable.
3. Provide users with a quality indicator or warning in Garmin Connect when HRV data shows signs of artifact.
Appreciate the excellent products and continuous improvements—just hoping we can refine this important metric.
Thanks,
Johnny Andersson
