I’m looking for the most reliable device(s) to measure continuous HRV (throughout the day) and sleep quality/length. Ideally this would be one wearable but it seems that most wearables that measure sleep can’t measure HRV reliably due to motion artifacts (see eg: https://www.quora.com/Is-there-any-wristband-activity-tracker-that-tracks-HRV-reliably-enough).
My research is taking me in the direction of the Polar M400 (for sleep tracking)+ Polar H7 band (for continuous HRV) as it probably makes most sense to be operating within one ecosystem for data handling but I have some doubts over the quality of the M400’s sleep tracking.
Would be great to hear from others if you have any experience or recommendations here?