How to read your Withings heart data

Withings mentions HRV data only in general terms in its developer documentation, without naming a field. We have not confirmed which HRV Withings reports or how it is computed.

Resting heart rate and sleep are useful on their own: read them against your own recent weeks.

HRV type: Not confirmed.

Compare a night with your own usual range over the last weeks, not with another person or another device. A single low night is most often a reaction to something specific — a short night, alcohol, an infection, stress or hard training. Several days below your range together with a higher resting heart rate and feeling unwell are a reason to rest.

Scores such as Readiness, Recovery, Nightly Recharge or HRV Status are each maker’s own algorithm. Two devices on the same night can show different HRV numbers because they measure at different times and with different formulas; neither is “wrong”.

Withings has a public API that does not require a contract. We are checking whether it provides HRV before deciding on a connection, so nothing is planned yet.

Through Apple Health

We have not confirmed that Withings writes HRV to Apple Health, so we do not promise that your Withings HRV will appear in ONDA. If your device is not Apple Watch, ONDA can still measure your pulse with the iPhone camera, along with a breathing-rate estimate. The camera gives pulse, not HRV.