Session effort
Hard minutes count differently.
Workout load weights duration and heart-rate intensity, so a short hard session can affect strain differently from an easy session of the same length.
Apple Watch readiness
Metric turns recent Apple Watch workout duration and heart-rate intensity into a strain and readiness view. It compares fast-changing short-term load with your slower-moving baseline, so you can see whether training is light, balanced, or accumulating. Treat the score as context for your own judgment, not an instruction.

The useful answer
Metric assigns workout effort from duration and heart-rate intensity, then lets recent sessions fade at different rates. Short-term load reacts quickly; the longer baseline changes more slowly. The relationship between them helps show whether strain is building or settling.
A harder session adds recent load and can lower the score. Easier days let that load settle. Metric reviews up to 90 days of available workouts and includes today’s training; you do not need to wait 90 days to see a number.
Metric’s 0–100 scale describes training strain. Apple’s separate Readiness app uses a 0–10 scale with activity, vitals, and sleep. Sleep and HRV can be reviewed alongside Metric’s meter, but they are not direct inputs to it.

Inside Metric
Every summary should lead back to the signal, date range, or source that shaped it.
Session effort
Workout load weights duration and heart-rate intensity, so a short hard session can affect strain differently from an easy session of the same length.
Personal baseline
Exponential decay lets new workouts move short-term load quickly while the chronic baseline responds more gradually.
Explainable ranges
The 0–100 view translates the load relationship into readable ranges and leaves the underlying workout list close at hand.
How it works
Allow Metric to read workouts and relevant heart data from Apple Health. Check that recent Apple Watch sessions have synced into Health.
Use the Training Readiness tile on Metric Home. If it is not in your layout, add it while customizing Home. A higher score means lower accumulated training strain.
Review recent workouts and their intensity, then check sleep and how you feel. Missing history or permissions can leave the meter with less context.
What to know first
A good fit if
Probably not for you if
Common questions
No. Apple Readiness combines activity, vitals, and sleep on a 0–10 scale. Metric uses a separate 0–100 workout-load model. Compare their inputs and trends rather than converting one number into the other.
Look for the Training Readiness tile on Home. You can include it in your customized Home layout. The meter summarizes accumulated workout strain; open your workout history to inspect the sessions behind it.
Low recorded workout load can produce a high score even when sleep is poor or you feel unwell. Check whether workouts and heart data are present in Apple Health and permitted in Metric, then review sleep and your own symptoms separately.
Metric uses available workout duration and heart-rate intensity to estimate session load, then compares fast-changing recent load with a slower baseline.
It means accumulated training strain is lower in Metric’s model. It does not capture every physical or life factor, so the number still needs your context.
The view can respond as workouts arrive, but a longer stretch of consistent data gives the chronic baseline more personal history.
Sources and context
Official platform documentation and original research are linked for context, not used to overstate what one app view can conclude.
Apple Support
Apple’s own feature has different inputs and a different scale from Metric’s training-load model.
Apple Support
Apple describes how Watch measures heart rate and HRV, along with fit, sampling, and reliability considerations.
Apple Developer
Official documentation for HealthKit’s category-by-category read and write permissions, including limited-history access.
Journal of Athletic Training / PubMed
A prospective cohort study of one athlete population. It is useful context for load monitoring, not a universal injury rule or individual prediction.
Metric for iPhone
Connect only the categories you choose. Start with the dashboard, then go deeper when a trend earns your attention.