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Field note 07 · Wearable comparison

Apple Watch and Garmin Readiness Disagree: What to Check First

Two scores, two answers. A practical way to check the information behind them before changing your plans.

You open two apps and get two different answers about the day ahead. One looks encouraging; the other is more cautious. Before changing your training plan, find out whether the apps are answering the same question with the same information.

The useful outcome of this check is a short explanation of the disagreement: different scales, different timestamps, incomplete records, or a difference you cannot yet explain. You do not need to pick a winning device to get there.

Why this question matters now

On 9 September 2026, Apple announced readiness for Apple Watch Series 12 and Ultra 4. People comparing those watches with Garmin now have another pair of similar-looking numbers to interpret.

First, keep the original scale

Here is a small comparison drawn from the manufacturers’ documented categories:

Apple readiness

7 / 10

Documented scale: 0–10

Category for this example
Ready · scores 5–7
Documented devices
Apple Watch Series 12 and Ultra 4

Apple’s score definitions

Garmin Training Readiness

70 / 100

Documented scale: 1–100

Category for this example
Moderate · scores 50–74
Model checked
Garmin Forerunner 965

Garmin’s score definitions

Examples of category lookup, not paired readings from a person.

Multiplying 7 by 10 changes the number’s presentation. It does not establish that Apple and Garmin measured the same quantity or drew the same conclusion. Neither cited manual supplies a conversion between the systems.

Keep both original values and their labels in your notes. Avoid merging them into an average readiness score: the result would introduce a new formula without showing what it means.

Check the time before the number

Apple describes activity, vitals and sleep as contributors to readiness. Garmin lists last night’s sleep score, recovery time, HRV status, acute load, and recent sleep and stress history. Both describe changes during the day. See the Apple calculation notes and Garmin calculation notes.

A screenshot from breakfast and a score viewed after a workout are not a controlled comparison. Record the time of each reading and whether it was taken before or after activity. If the times differ, mark that difference before trying to explain it as better sleep or worse recovery.

Reading both apps at the same time does not make their algorithms equivalent, but it removes one avoidable ambiguity from your comparison.

Check what each app actually received

Open the relevant sleep and workout records in each app. Check dates, durations, missing entries and the device that supplied them. A connected app is not proof that every category has arrived for every day.

For Apple Health, open the category and subcategory you want to inspect, then scroll to Data Sources & Access. Source priority can also be managed there. Review the existing records before changing settings, so you preserve an explanation of what you saw. Apple’s data management instructions explain the controls.

Do not delete records simply to make the two displays agree. If a workout is absent from one history, record that as a data difference. If you cannot inspect an input, write “not verified.” That is more useful than silently assuming it was identical.

If Apple shows no score at all, follow its current setup checklist. An absent score belongs in a setup investigation; it is not a zero.

A new watch can change the HRV question, not just the number

Apple’s 9 September 2026 announcement describes two HRV variants: Recovery HRV and overall HRV. Its support instructions say Recovery HRV on the specified new models is sampled while the wearer is still, so the available measurement count varies with activity. These are manufacturer descriptions, not our independent validation of either metric. Apple’s announcement · Recovery HRV instructions.

The practical consequence is a question to verify: does the line after a watch or software change represent the same metric, sampling context and summary as the line before it? The label “HRV” and the same unit do not answer that by themselves.

1. Exact metric

Copy the full label and unit. If the calculation method is documented, record it. Do not silently equate overall HRV, Recovery HRV, a nightly average or HRV status.

2. Sampling context

Record whether the source describes overnight, daytime, stillness or another condition. Separate an individual measurement from a summary of measurements.

3. Window and coverage

Keep the observation period and available coverage beside the value. “Viewed this morning” is not a measurement window. Mark a gap rather than copying the last value forward.

4. Device and version

Note model, software and the date of a switch or update. Preserve that boundary in a trend; do not make a before/after line appear continuous by deleting the note.

5. Source and destination

Check the exact category shown in the original app and the destination. A connected watch does not establish that a newly introduced metric has been exported or imported.

6. Comparison decision

Write “same documented metric and context,” “different metric” or “not verified yet,” with the reason. This is a bookkeeping decision, not a verdict on health or recovery.

Synthetic comparison: an older note says only “HRV, 42 ms”; a new one says “Recovery HRV, 48 ms.” You can report the two displayed values. Without the old metric definition, windows and sampling context, you cannot call the difference a six-millisecond improvement in the same measure.

If the passport exposes a change, keep separate labelled segments until comparability is established. More samples can change what a summary includes; they do not supply a universal conversion between products or variants. This article provides no cross-device conversion and makes no claim that Nutrinaut currently imports the new Apple metric.

Apple’s current readiness guidance, updated 6 October 2026, still describes a general-wellness score with activity, vitals and sleep inputs; it should not be the sole basis for exercise safety. A better-described HRV record does not remove those limits. Current calculation notes and safety scope.

Make the comparison useful

Use a separate column or note for each product. Keep personal health details in your own notes; you do not need to send them to Nutrinaut to use this method.

  1. Exact device model and software version.
  2. Metric name, original value and displayed label.
  3. Date, local time and time zone of the reading.
  4. Before or after today’s workout?
  5. Last night’s sleep record present?
  6. Latest workout present, with matching date?
  7. Input details visible in the app.
  8. Missing or unverified records.
  9. Recent device, software or source change.

Two A4 pages for printing and private notes. The PDF uses the same method as the editable text version; it does not send your answers to Nutrinaut.

Then write one sentence:

I can explain the difference by ______. I still cannot verify ______.

If the honest answer is “I do not know,” keep it. The worksheet is complete when you have separated known differences from unanswered questions, not when you have forced the scores to agree.

Decide what the disagreement tells you

Different reading times

Next step: record another pair under comparable timing.

The original pair does not isolate a product difference.

Missing sleep or workout data

Next step: check the source, permissions and sync status in the affected app.

The two histories differ; the effect on the score remains uncertain.

Different scores, complete-looking histories

Next step: keep separate trends and consult each product’s input explanations.

The disagreement alone does not identify the more accurate device.

A recent device or software change

Next step: mark that date in your record and retain the version information.

A measurement-system change belongs in the explanation; it does not prove a health change.

My editorial recommendation is to make the question smaller: “What changed in the information?” is easier to investigate than “Which watch knows how recovered I am?” The comparison can help you fix a missing record or ask a better support question, even when it cannot settle a training decision.

Apple explicitly limits readiness to general wellness and says it should not be the sole basis for exercise safety. A reassuring score should not override concerning symptoms. Read Apple’s stated limits.

Continue with the underlying question

If your problem is missing or mixed data, use the wearable data source checklist. For the broader limits of recovery summaries, read How to Read Recovery Signals Without a Readiness Verdict.

If your question is simply how recorded sleep adds up across a week, the Sleep Debt Planner explains its arithmetic separately from a manufacturer’s readiness score.

Sources and scope

Documentation rechecked on 15 October 2026; this update adds the HRV metric passport. Manufacturers may change features or requirements. These sources support product descriptions; the comparison worksheet is an editorial aid, not a validated assessment of recovery or an evaluation of Nutrinaut’s accuracy.

  1. Apple: introducing Apple Watch Series 12 · 9 September 2026.
  2. Apple Support: understand your readiness score · source updated 6 October 2026.
  3. Garmin Forerunner 965 manual: Training Readiness · Version 11, April 2026.
  4. Apple Support: manage Health data and sources.
  5. Apple: September health and fitness announcement · 9 September 2026; manufacturer description of two HRV variants.
  6. Apple Support: monitor your heart rate, including Recovery HRV · source dated 14 September 2026; availability varies by model and region.

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