Review

Wearable health sensors, checked against clinical equipment

Heart rate is basically solved. Everything the marketing pages put next to it is not.

Rania Saab

Published 28 July 2026
10 min read
11.4k reads

Wearable health sensors, checked against clinical equipment — XENVORA Photograph: Smart Watch, Design by Matt / Stocksnap (CC0) · Licence

7.9 Verdict score

Every device runs the same instrumented suite: sustained load, thermal logging, power draw at the wall, and a two-week daily-use period before a score is assigned.

We wore five devices simultaneously alongside a chest strap and a pulse oximeter borrowed from a sympathetic clinic. Resting heart rate agreed within two beats on every unit.

Where confidence collapses

Blood oxygen during movement, respiratory rate and anything described as a "stress score" diverged wildly — not just from the reference, but from each other on the same wrist.

Sleep staging deserves its own warning. Total sleep time was close; the breakdown into stages disagreed with the reference more often than it agreed.

Our 7.9 goes to the device that ships the fewest invented metrics and exports raw data you can check yourself.