Recovery
What recovery and readiness scores are built from, why they drop, and what they can honestly tell you.
Recovery and readiness scores try to tell you how prepared your body is for the day, usually by blending HRV, resting heart rate, sleep, and recent strain. They're useful as a trend and easy to over-read on any single day. Here's what these scores are actually built from, what moves them, and where the research supports leaning on them.
| Device | What they call it | What it actually measures |
|---|---|---|
| Whoop | "Recovery Score" (0-100) | HRV (the single most influential input), RHR (measured during deepest sleep), plus respiratory rate, sleep, skin temp, blood oxygen. |
| Oura | "Readiness Score" (0-100) | Recent activity, sleep patterns, RHR, HRV, body temperature. |
| Garmin | "Body Battery" | RMSSD-derived HRV, daytime stress patterns, sleep quality/duration. |
| Fitbit | "Daily Readiness Score" (Premium-only) | HRV, RHR, sleep quantity and architecture, weighted roughly equally with recent activity. |
| RingConn | "Dynamic Health Balance" | Weighs recent activity, sleep, and stress into a readiness-style number, though RingConn also reports separate Lifestyle and sleep-specific recovery metrics rather than one consolidated figure. |
| Samsung Galaxy Watch | "Energy Score" | Weighs sleep time, sleep consistency, and sleeping heart rate/HRV into one daily number, leaning more on sleep consistency than same-day activity or stress. |
| Amazfit | "Readiness Score" and "BioCharge" (two separate features) | Readiness Score generates once each morning from overnight data; BioCharge updates continuously through the day from largely the same inputs. |
| Withings ScanWatch | "Readiness Indicator" | Draws on nightly HRV, temperature, sleep, and breathing data. Exact weighting formula isn't publicly documented. |
| Polar Vantage | "Recovery Pro" and "Orthostatic Test" | Combines a published two-position (lying/standing) heart-rate and RMSSD protocol with long-term HRV data and subjective feedback, a real peer-reviewed evidence base most competitors' recovery scores don't have. |
Despite all four using similar inputs and similar-sounding names ("Recovery," "Readiness"), a real peer-reviewed evaluation found these composite scores are not methodologically equivalent to each other. Direct comparison between, say, a Whoop Recovery Score and an Oura Readiness Score on the same day isn't scientifically sound, even though both numbers claim to answer the same question.
Device measurement accuracy: Emerging · see the fileSources: Whoop's own recovery methodology page (whoop.com) and Oura's own readiness-score support page and blog (ouraring.com), both primary. Fitbit's Daily Readiness Score description from secondary comparison sources. The composite-score-inequivalence claim traces to a real peer-reviewed paper, Fischer & Reiter, "Readiness, recovery, and strain: an evaluation of composite health scores in consumer wearables," 2025, doi:10.1515/teb-2025-0001.
What's inside the number and what it can and can't tell you.
See how you compareIn the works
- Recovery Metrics That Matter Most
We publish each piece when the research behind it is done, not before. Check back, or start with the benchmark above.