How to read your WHOOP HRV

Recovery is a score from 0 to 100%, shown in three colours. WHOOP says it uses HRV, resting heart rate, sleep and respiratory rate, compared with your own baseline.

WHOOP’s developer documentation names the HRV value hrv_rmssd_milli: it is RMSSD, in milliseconds, attached to each Recovery.

Recovery is WHOOP’s own algorithm. The formula behind composite scores like this is not published by the makers, so treat the percentage as a summary and look at the HRV and resting heart rate underneath it.

HRV type: RMSSD, in milliseconds (in Recovery).

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”.

WHOOP has a public developer API. We plan a direct connection, but it is not available yet. WHOOP approves apps in stages with a manual review, so we cannot give a date.

Through Apple Health

We have not confirmed that WHOOP writes HRV to Apple Health, so we do not promise that your WHOOP 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.