Recovery score explained: HRV, resting heart rate and your 7-day baseline

A recovery score is a daily number that compares this morning's heart rate variability (HRV) and resting heart rate (RHR) with your own recent baseline, then adjusts for last night's sleep. HRV above your normal range, RHR at or below it and enough sleep tend to give a high score. Most systems need about 7 nights of data before that baseline is reliable.

The score is a summary, not a measurement. It is only as good as the signals under it and the baseline it compares them with. This guide explains each input, why the baseline matters more than the raw number, how the major brands calculate their versions, and what a recovery score can and can not tell you.

What is a recovery score?

A recovery score is a single number that estimates how ready your body is to handle physical stress today. It combines overnight or morning signals from the autonomic nervous system (mainly HRV and resting heart rate) with sleep data, and compares them with your own recent history. Brands also call it a readiness score.

The idea comes from sports science. Coaches have tracked morning heart rate and HRV in athletes for decades because both respond to training load, sleep, illness and stress. A consumer recovery score automates that routine: the device records the signals at night, compares them with your baseline and turns the result into one number with a color.

Three points apply to every brand:

• Relative, not absolute: the score compares you with you. A 25-year-old endurance athlete and a 60-year-old beginner can both score high on the same day.
• Morning snapshot: most scores are fixed when you wake up. Apple Readiness and Garmin Training Readiness also update during the day.
• Wellness, not diagnosis: Apple states that Readiness "is a general wellness feature" and should not replace professional medical judgment. The same applies to every recovery score.

What goes into a recovery score?

Most recovery scores use three core inputs: HRV, resting heart rate and sleep. Some add respiratory rate, skin or wrist temperature and recent training load. Each input is compared with your own baseline, scored, weighted and added together. Brands publish the inputs but usually not the exact weights.

Input	What it reflects	Direction that raises the score
Heart rate variability (HRV)	Variation between heartbeats, linked to parasympathetic (rest and digest) activity	Higher than your baseline
Resting heart rate (RHR)	Heart rate at full rest, usually during sleep	At or below your baseline
Sleep	Duration, and in some apps stages and timing	Close to or above your sleep need
Respiratory rate	Breaths per minute during sleep	Stable, inside your normal range
Skin or wrist temperature	Overnight temperature deviation	Stable, inside your normal range
Training load	Recent workouts compared with your longer history	Not far above your usual load

Caption: inputs listed by Whoop, Oura, Garmin and Apple on their own pages (see sources). Not every brand uses every input.

Why HRV carries the most weight

HRV is the variation in time between consecutive heartbeats. Shaffer and Ginsberg (2017) describe the root mean square of successive differences (RMSSD) as the main time-domain HRV measure used to estimate vagally mediated, or parasympathetic, changes. When you are rested, the vagus nerve tends to slow and vary the heart rhythm more, so HRV tends to be higher. After hard training, alcohol, poor sleep or illness, HRV tends to drop below your normal level.

There are two common HRV numbers. Apple Watch stores overnight HRV in Apple Health as SDNN (the standard deviation of normal-to-normal intervals), and iOS 27 adds an RMSSD type. Many other devices and apps report RMSSD. They are not directly comparable, so a recovery score must compare each person with their own baseline in the same metric. Our guide to RMSSD vs SDNN covers the difference, and what is a good HRV covers typical ranges.

Why resting heart rate is the second signal

Resting heart rate is the number of heartbeats per minute at complete rest. The normal adult range is 60 to 100 bpm, and well-trained athletes can sit at 40 to 60 bpm (American Heart Association). For recovery, the absolute number matters less than the change: a resting heart rate a few beats above your usual level is commonly associated with incomplete recovery, heat, dehydration, alcohol or the start of an illness. See resting heart rate by age for typical ranges.

Why sleep is in every score

Short sleep tends to push HRV down and resting heart rate up the next morning. Adults need 7 or more hours per night (AASM and Sleep Research Society consensus). Some apps use a full sleep score here, which also weighs stages and bedtime consistency. Our sleep score guide explains those parts.

Why does the baseline matter more than the number?

The baseline is your own normal range for each signal, usually a rolling average of recent nights. It matters more than the raw value because HRV and resting heart rate differ widely between healthy people. A single reading tells you little. A change against your own average is what a recovery score is built to detect.

Two facts support this design:

1. Individual ranges are wide. Shaffer and Ginsberg (2017) review HRV norms and show that values decline with age, differ between men and women and depend on recording length. An HRV of 35 ms can be normal for one person and low for another.
2. Averages beat single days. Plews et al. (2013) followed 10 runners through a 9-week training block. Changes in a one-week average of log-transformed RMSSD correlated very strongly with changes in 10 km running performance (r = -0.76), while a single-day value showed only a small correlation (r = -0.17). The same pattern held for resting heart rate.

The practical rule: one red day is information, not a verdict. A trend that moves for 3 or more days is a stronger signal.

How long does it take to build a baseline?

Most systems need about one week of nightly data before the baseline can separate a real change from normal noise. Apple's Readiness app needs at least 7 nights of overnight vitals. Garmin shows a load ratio after about 2 weeks of training. Oura's sleep and activity balance contributors look back two weeks.

System	Baseline or setup period	Source
Apple Readiness (Series 12, Ultra 4)	At least 7 nights of overnight vitals	Apple Support
Apple Vitals app	7 nights to set your typical range	Apple Support
Oura Readiness	Two weeks for sleep balance, sleep regularity and activity balance	Oura
Garmin load ratio	About 2 weeks of training	Garmin manual
Svanu recovery	Provisional after 3 nights, full at 7	Product fact sheet

Caption: setup periods as stated by each company, as of October 2026.

How do Whoop, Oura, Garmin and Apple compare?

All four compare overnight signals with your own baseline, but they use different scales and inputs. Whoop Recovery runs from 0 to 100%. Oura Readiness runs from 0 to 100. Garmin Training Readiness runs from 1 to 100. Apple Readiness runs from 0 to 10. A number from one brand can not be read on another brand's scale.

Score	Scale and bands	Main inputs listed by the company
Whoop Recovery	0–100%: green 67–99, yellow 34–66, red 1–33	HRV, resting heart rate, sleep, respiratory rate
Oura Readiness	0–100: 85+ optimal, 70–84 good, below 70 pay attention	Sleep, sleep balance, sleep regularity, previous day activity, activity balance, resting heart rate, HRV balance, body temperature, recovery index
Garmin Training Readiness	1–100: prime 95–100, high 75–94, moderate 50–74, low 25–49, poor 1–24	Sleep score, recovery time, HRV status, acute load, 3-night sleep history, 3-day stress history
Apple Readiness	0–10: go for it 8–10, ready 5–7, pace yourself 2–4, recover 0–1	Activity and Training Load, daytime and overnight vitals, sleep score

Caption: each company's own documentation, as of October 2026. Weights are not published.

What about Garmin Body Battery?

Body Battery is a different idea. Garmin describes it as an estimate of reserve energy on a scale of 5 to 100, built from HRV, stress level, sleep quality and activity. It drains during the day and recharges during sleep. A recovery score is a morning judgment about readiness to train. Body Battery is a running energy gauge that changes all day.

For brand-specific detail, see how Whoop calculates recovery and how to get a recovery score on Apple Watch.

What is a good recovery score?

A good recovery score is one at or above your own usual range on the scale your app uses. On Whoop that is green (67% or higher), on Oura 85 or higher, and on Apple Readiness 8 to 10. Day-to-day movement within your normal band is expected and does not need action.

More useful than any single threshold:

• Look at the trend. A 7-day average that slowly rises during a training block is a good sign. A 7-day average that slowly falls while training load climbs is a warning sign.
• Read the inputs, not only the total. A low score driven by short sleep calls for a different response than a low score driven by a resting heart rate 8 bpm above normal.
• Match the score to how you feel. If the score is red and you feel fine, a lighter session is a low-cost choice. If the score is green and you feel unwell, trust the symptoms.

What lowers a recovery score?

Anything that shifts the autonomic nervous system toward stress can lower a recovery score. The most common causes are hard training, short or late sleep, alcohol, illness, heat, high altitude, travel and psychological stress. Apple lists medications, elevation, alcohol and illness as common reasons that overnight vitals move outside the typical range.

Cause	Typical overnight pattern
Hard or unusually long workout	HRV down, RHR up
Alcohol in the evening	HRV down, RHR up, sleep quality lower
Short sleep	HRV down, sleep input low
Start of an illness	RHR up, HRV down, temperature or breathing rate may rise
Heat, travel, altitude	RHR up, HRV down

Caption: general directions only. How large the change is and how long it lasts differ from person to person.

Our guides on alcohol and HRV and heart rate when sick go deeper on two of these. If several signals stay off for days and you have symptoms such as fever, chest pain, shortness of breath or unusual fatigue, see a doctor. A recovery score can not tell you why your numbers changed.

Should you train based on your recovery score?

You can use a recovery score to adjust intensity, but not as the only guide. In a small trial by Kiviniemi et al. (2007), men who chose hard or easy runs each day from their morning HRV improved peak oxygen uptake from 56 to 60 mL/kg/min over 4 weeks. A group on a fixed plan did not change significantly, although the difference between the two groups was not statistically significant.

That study had 26 participants, so it shows feasibility, not a rule for everyone. A simple way to use the score:

Score state	Reasonable training choice
At or above your normal range	Planned hard session is fine if you feel well
Slightly below normal for 1 day	Keep the session, lower the volume or intensity
Well below normal for 2–3 days	Easy aerobic work or rest, check sleep, alcohol and stress
Low with symptoms of illness	Rest and talk to a doctor if symptoms continue

A recovery score works best together with a measure of load. Strain shows how hard today was, and the acute:chronic workload ratio shows how this week compares with the last six. Read what is strain and the acute:chronic workload ratio for both. When load stays high and recovery stays low for weeks, the pattern can resemble the early signs in overtraining symptoms.

How is a recovery score different from sleep, strain and stress scores?

A recovery score answers one question: how ready is your body for load today? A sleep score rates last night only. A strain score measures how much load you took on. A stress score tracks physiological load from signals such as resting heart rate and sleep debt. They share inputs, but each answers a different question.

Score	Question it answers	Time frame
Recovery or readiness	How ready am I for physical load today?	This morning, against your recent baseline
Sleep score	How well did I sleep?	Last night
Strain	How much load did I take on?	Today
Training load	Is this week a jump from my usual?	Last 7 days against the last several weeks
Stress score	How much physiological load am I under?	Today and recent days

Caption: general definitions. Each app sets its own inputs and scales.

Read them together. A low recovery score after a high-strain day is expected. A low recovery score after a rest day and a good sleep score may point to something else, such as stress, alcohol or the start of an illness. See stress score for how wearables estimate stress from HRV.

What can a recovery score not tell you?

A recovery score can not diagnose illness, measure muscle damage directly or predict an injury. It reflects heart rhythm and sleep signals that respond to many causes at once. A low score says something changed. It does not say what changed, and it is never a substitute for medical advice.

Other limits to keep in mind:

• Device error: wrist sensors lose accuracy with a loose fit, movement or cold skin. One noisy night can move the score.
• Missing inputs: if your device does not record HRV overnight, the score has fewer signals and is less certain.
• Context the device can not see: a stressful meeting, a long flight or a new medication can change HRV and heart rate without any training at all.

How Svanu calculates recovery

Svanu compares this morning's HRV and resting heart rate with your own recent baseline, plus last night's sleep. The baseline starts as provisional after 3 nights and becomes full at 7. Every score shows its inputs and what moved it, so you can see whether sleep, HRV or resting heart rate changed today's number.

How it handles different devices:

• Apple Watch: reads HRV (SDNN) and resting heart rate from Apple Health.
• Other devices that write to Apple Health (such as Garmin, Oura or Withings via their Apple Health sync): if the device does not write HRV, recovery uses resting heart rate and sleep. If resting heart rate is missing, the app derives it from heart-rate samples as the lowest 30-minute average during main sleep, and compares derived values only with derived values.
• iPhone only: a 20 to 30 second camera reading (finger on the rear camera and flash) measures RMSSD each morning. Camera readings are compared only with earlier camera readings, never with a watch's overnight SDNN. Learn more in measure HRV with your iPhone camera.
• No heart data at all: the app gives an estimate from sleep and how you feel in the daily check-in, and labels it as an estimate.

All scores are computed on the iPhone, and there is no health database on the server. The core app is free. You can see the full feature list on the Svanu home page.