Training readiness score explained, and how to use it tomorrow

Garmin calls it Training Readiness, Whoop calls it Recovery, Oura calls it Readiness, and PeakU calls it the Peak Score. They are all trying to answer one question before you decide how to train: how much can your body absorb today? Here is what goes into the number, why the number on its own is not enough, and a rule for using it.

What is a training readiness score?

A single number, usually 0 to 100, that estimates how well your body is placed to take on training today. It is not a measure of fitness and not a measure of how hard yesterday was; it is an estimate of recovery, built from signals your wearable collected overnight and over the past weeks. A high score means you are likely to execute a hard session well and adapt to it. A low score means the same session will cost more and give back less.

Every vendor packages it differently, but the question underneath is the same, which is why the inputs are the same too.

What goes into a readiness score?

Every serious readiness score blends the same four inputs with different weights: last night's sleep against your normal, HRV against your baseline, resting heart rate against your baseline, and recent training load relative to your average. Some add stress, skin temperature or menstrual phase. The maths is proprietary in every consumer product, which is a problem when the number surprises you and nobody can say why.

Notice that every row says "your own". A readiness score is a comparison with your history, never with a population. That is why a new device gives you nothing useful for two or three weeks: it has no history to compare against. What a good HRV looks like against your own baseline is covered in what is a good HRV for my age.

PeakU does this from your own data. A coach that reads everything you already track. Join the free beta →

Why does the number alone fail?

A 62 is not a plan. Most people either ignore the score after the novelty wears off or obey it superstitiously, resting on every low day until their fitness declines. A readiness number is only useful when it comes with two things: the reason it is where it is, and what to do about it today. Low because of a short night after a heavy leg day: keep the run, drop the intervals is coaching. 62 is a weather report.

The reason matters because the right adjustment depends on it. Low from a short night calls for dropping intensity, since skill and perceived effort are what sleep loss degrades first. Low from a big load spike calls for easy volume and patience. Low with a raised resting heart rate and no training explanation might be the start of a cold. Same number, three different days.

What is a good readiness score?

One inside your own normal band. Vendors colour the scale green, amber and red at fixed cut-offs, but your typical score is what matters. Someone whose scores usually sit in the 60s is not "amber" on a 58; someone who usually sits in the 80s is on a 65. Read it against your own distribution, and read the direction over the week before you read today's value.

Also distrust extremes in both directions. A very high score after an easy week is permission to execute the plan well, not evidence that you can double it. A very low score after one hard day is the hard day showing up on schedule.

How do you use a readiness score? A rule for tomorrow

1. If the score is in your normal band, do the planned session.
2. If it is low for one day and you slept, do the session but cap the hard part at two thirds.
3. If it is low for two or more days, or low with a raised resting heart rate, swap the hard session for easy volume and move quality later in the week.
4. If it is high, do not add work. High is permission to execute the plan well, not to freelance.

Easy volume on a low day means genuinely easy, in the lowest zones. Most people's easy pace is not; why most people train in the wrong zone explains the trap. And when the low score comes from sleep, the specific rule is in how much to train after a bad night.

Why do different devices give different readiness scores?

Different weights, different baselines, different measurement windows, and sometimes different sensors in different places on the body. Garmin's number is an energy budget across the day, Oura's leans on sleep and temperature, Whoop's on HRV during slow-wave sleep against strain. They answer slightly different questions and can all be right while disagreeing. The comparison in detail is in Garmin vs Oura vs Whoop recovery scores.

If you wear two devices, treat agreement as a strong signal and disagreement as a prompt to look at the raw inputs, resting heart rate and HRV, which are comparable in a way the scores are not.

What can a readiness score not see?

Anything that did not happen on your wrist. A strength session shows up as an hour of elevated heart rate with no idea what you lifted. A long walk, a cycling commute, a day on your feet at work, a stressful meeting: all of them cost recovery, and most of them are invisible or badly estimated. Pain is invisible. Appetite is invisible. Motivation is invisible, and the consensus view on overreaching treats it as real data.

So a readiness score is a strong prior and a weak verdict. When it disagrees with how you feel, the score is not automatically right. If you feel wrecked on a green morning, something it cannot see is going on; if you feel fine on a red one after an obviously hard day, the hard day is the explanation. The score earns trust by being right about the mornings you could not have predicted yourself, which is most of them, not by overruling the ones you could.

How the Peak Score differs

PeakU shows the score with its drivers ranked, so you can see that sleep did the damage and load did not. Every score comes with the call for the day and a one-line why, and the plan moves itself instead of waiting for you to interpret it. It reads your watch's own readiness score as one input alongside sleep, HRV and the lifting and running your watch never sees. The maths is deterministic and audited; the language model only explains it.

Hen Eytan · Founder, UPeak

Builds the UPeak apps and writes up the research behind them.