Methodology

What goes into
your recovery score

Arry uses sleep, HRV, resting heart rate, stress, and recent load. Each measurement is compared with your usual values.

Contents

  1. Core principles
  2. Which signals Arry uses
  3. Why personal baseline matters
  4. What the system does not claim
  5. How this connects to privacy

Core principles

Arry's recovery score is not a diagnosis or a prediction of performance. It helps you decide whether to raise today's load and shows which measurements affected the result.

  • the score uses several data points at once;
  • the main comparison is with your own baseline;
  • we avoid absolute claims such as “fully ready” or “not ready at all”;
  • you can see what affected the score, not only the result.

Which signals Arry uses

The data available depends on your device and Apple Health permissions. The main calculation uses:

HRV
Heart rate variability as one marker of nervous-system strain and adaptation.
Sleep
Sleep duration, quality, regularity, and stages when available.
RHR
Resting heart rate as a practical signal of accumulated fatigue and general state.
Load
Recent training and daily load so the last few days are not ignored.

Some features also use activity, stress, and workout history. Arry does not attempt to guess how you feel; it shows measurements worth considering before you add load.

Why personal baseline matters

Two people can have very different usual HRV, resting heart rate, and responses to the same amount of sleep. Arry compares readings with your range, not an abstract norm.

A better question is not “Is my HRV normal?” but “Has it changed from my usual level, and do sleep and heart rate point the same way?”

During the first few days after connecting HealthKit, Arry builds its starting values. Comparisons become more stable as more data arrives.

What to keep in mind

  • the same HRV value can mean different things for different people;
  • one poor night does not always equal a red day if the rest of the picture is stable;
  • a strong night does not erase accumulated fatigue from a hard block;
  • several matching signals are more useful than one reading in isolation.

What the system does not claim

Arry is not a medical device, does not diagnose illness, and does not replace a clinician. Recovery Score and other in-app recommendations are support tools for day-to-day load management and self-observation.

  • we do not claim to predict performance perfectly from one score;
  • we do not claim that a low score automatically means a health problem;
  • we do not treat any single system as a full replacement for subjective state and judgment.

How this connects to privacy

Arry uses only data needed for a feature and processes core measurements on the device. You should be able to see which readings affect the score and why.

More on data handling is on the privacy page. More on who builds Arry and how the site materials are prepared is on the about page.