At least my high end Garmin watch with built-in optical HRM doesn't consider the OHRM accurate enough for HRV measurement purposes. Instead I have to pair a hea

At least my high end Garmin watch with built-in optical HRM doesn't consider the OHRM accurate enough for HRV measurement purposes. Instead I have to pair a heart rate strap and use that for an HRV measurement. This seems typical: https://elitehrv.com/compatible-devices https://elitehrv.com/compatible-devices