What Is a Readiness Score? How Recovery Metrics Work

Nearly every wearable brand builds its readiness or recovery number from the same handful of overnight inputs, even though the exact formula and the name on the label differ. The core input is heart rate variability, usually captured as RMSSD during your deepest, most stable sleep window. Resting RMSSD commonly falls somewhere between 20 and 100 or more milliseconds depending on the person, and a higher reading generally reflects a more rested, flexible nervous system. See AI HRV Training for how to turn that raw HRV trend into actual training decisions instead of just watching the number.

Alongside HRV, most algorithms weigh your resting heart rate, since a resting rate that runs a few beats higher than your personal baseline is a reliable sign your body is still working through stress, illness, or unabsorbed training. Sleep duration and stage quality, how much deep and REM sleep you actually got rather than just hours in bed, factor in heavily too. Several devices add a skin temperature deviation, which flags anything from a warm bedroom to the earliest signs of getting sick, and a recent training load or strain figure that accounts for how hard you have pushed over the last several days.

It is worth being precise about what the score is and is not. A readiness score is a same-morning read on autonomic nervous system load, not a fitness score, not a health grade, and not a prediction. It tells you how much your body has recovered from what you have already done, and by extension how much capacity it likely has for today. It does not measure your VO2 max, your strength, or your long-term health trajectory.

Oura scores readiness on a 0 to 100 scale with three bands: 85 and above is optimal, 70 to 84 is good, and anything below 70 is flagged as pay attention, meaning something, poor sleep, alcohol, illness, or heavy training, is likely suppressing recovery. Oura leans heavily on HRV, resting heart rate, body temperature, and sleep quality from the prior night, weighted against your personal baseline.

Whoop uses a 0 to 100 percent scale with a color-coded traffic light: green (67 to 100 percent) means your body is primed for strain, yellow (34 to 66 percent) is moderate readiness, and red (0 to 33 percent) signals your body needs rest. Whoop’s recovery is built mainly from HRV and resting heart rate captured during your most recent sleep, benchmarked against your own rolling average rather than a population norm. See what AI can do with Whoop data for how that recovery percentage looks once it is cross-referenced against everything else you log.

Garmin takes a different framing with Body Battery, which runs 0 to 100 but presents recovery as a charge and drain metaphor rather than a single daily verdict. Your battery charges overnight based on sleep quality and stress load, then drains throughout the day as you train, work, and accumulate stress, so it updates continuously rather than resetting once each morning.

The important takeaway across all three is that these numbers are not cross-comparable, not between devices and not between people. Each company weights its inputs differently, calibrates against a different baseline window, and in some cases pulls from slightly different sensors. An Oura 75 and a Whoop 75 percent are not measuring the same thing, and treating them as interchangeable will only produce confusion.

There is no single universal target, and any chart that gives you one number to aim for is oversimplifying. HRV and readiness baselines trend downward with age as the autonomic nervous system becomes a little less flexible over the decades, so a well-trained person in their twenties or thirties will often sit noticeably higher than a sedentary person in their fifties or sixties, and that gap is normal rather than a warning sign for either person.

Training status matters just as much as age. People who train consistently tend to run a higher baseline readiness and, just as importantly, bounce back to that baseline faster after a hard session or a rough night than someone who is deconditioned or inconsistent. That resilience, how quickly the number recovers after a dip, is often a more useful signal than the absolute score on any given day.

Short-term dips are also completely normal and not something to be alarmed by. A late night out, a few drinks, a red-eye flight, the first day of a cold, or a brutal leg day can all knock ten or twenty points off a readiness score for a day or two without meaning anything is wrong. The number that actually matters is not today’s reading in isolation, it is whether today’s reading is close to your own personal 30 to 60 day baseline. Good is relative to you, not to a fixed population target.

The single best habit for using a readiness score well is watching a 7-day rolling average alongside the daily reading rather than reacting to any one morning’s number. A single low day, even a sharply low one, is almost always noise, the product of one bad night, one hard workout, or one glass of wine too many. Treat it as information, not an emergency.

The real signal is a sustained slide, three or more consecutive days trending downward against your rolling average. That pattern is the cue to actually scale back training intensity, prioritize an extra hour of sleep, or take a genuine rest day, rather than a single rough morning that would have you second-guessing every planned workout.

It also helps to correlate dips with what you actually did, late alcohol, poor or short sleep, travel across time zones, the onset of illness, or a stretch of unusually heavy training. Over a few months, most people start to see their own personal pattern emerge, which behaviors reliably tank their readiness and by how much, and that pattern becomes far more actionable than any single day’s score ever could be.