Training readiness score explained, and how to use it tomorrow morning

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?

What goes in

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.

Why the number alone fails

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 quietly 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.

A rule you can use 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.

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. The maths is deterministic and audited; the language model only explains it.