How to read your Oura HRV

Oura’s Readiness score combines several inputs: HRV, resting heart rate, body temperature, sleep, activity and, where relevant, the menstrual cycle. It is Oura’s own algorithm, not a medical measure.

Inside Readiness, “HRV Balance” compares your recent HRV with your longer-term level: Oura describes it as a 14-day weighted average compared with your average over about two months.

Oura’s developer documentation exposes HRV as an average over your sleep (average_hrv). Oura’s help pages describe possible reasons for a change with “may” — a change is a signal to look at, not a cause.

HRV type: Night-time average (during sleep).

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”.

Oura has a public API. We plan a direct connection, but it is not available yet and we cannot give a date. Oura says data from current rings is only available through its API with an active Oura Membership.

Through Apple Health

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