Google has confirmed that an update to its Health app, version 5.12, is preventing some Fitbit users from viewing daily vitals including heart rate variability, resting heart rate, blood oxygen, breathing rate and skin temperature. A Google spokesperson said the company is investigating and working on a fix, though the underlying data appears to still be recorded correctly even when it isn't displayed.
androidauthority.com
· 2026-11-12
Google detailed how Fitbit devices measure heart rate variability, using an optical sensor to estimate gaps between heartbeats and applying the RMSSD formula to produce a millisecond-based score. The metric draws on the longest sleep period of at least three hours within the prior 24 hours, and results appear in Google Health under Health > Vitals > Heart rate variability, showing daily and long-term trends plus a personal range from up to 30 days of data.
engadget.com
· 2026-11-01
Apple's new $799 Watch Ultra 4 pairs a redesigned sensor array—32 electrodes arranged like flower petals—with the new S11 chip, enabling heart-rate readings every 5 seconds and HRV checks every 5 minutes, far more frequent than prior models. That increased sampling powers a new Readiness score that updates throughout the day rather than relying mainly on overnight data, plus a Daytime toggle in the Vitals app to view daytime alongside nighttime metrics.
cnet.com
· 2026-09-10
Apple's Series 12 smartwatch features a redesigned sensor layout with more diodes and electrodes for greater skin contact, enabling more frequent and accurate heart rate and HRV readings. This data powers a new Readiness app that generates a daily 0-10 score based on activity, sleep and vitals, alongside a redesigned Health app with Apple Intelligence summaries for compatible iPhones.
engadget.com
· 2026-09-10
Apple unveiled the Watch Series 12 and Ultra 4, both built around a new S11 chip and a redesigned Health Sensing System aimed at improving heart rate and heart rate variability tracking. The system uses ring-arranged photodiodes, larger electrodes, and bigger, more efficient green LEDs to measure heart rate every five seconds, with HRV readings taken up to 24 times more often than before. Preorders for both models are now open.
arstechnica.com
· 2026-09-09