Understanding starts
with the explanation.

Begin with the source.

Your wearable records data. Its companion app or health service makes compatible records available. With permission, Stride reads those records through your chosen source: Apple Health on iPhone or Google Health for Fitbit data.

A source record and a Stride estimate are different. Recorded sleep stages are estimates supplied by the source, while recovery and activity load use Stride’s own wellness calculations. Stride does not independently measure your pulse, sleep stages or oxygen level.

Only one selected source drives Today and Trends. Switching sources does not combine their totals. Different devices, recording schedules and measurement methods can produce different histories.

Check compatibility

Compare against your own history.

Personal baselines use prior observations rather than treating everyone as interchangeable. At least seven observations are required before a baseline is available. The current record can then be understood alongside that history.

A baseline is a reference, not a statement that your usual pattern is medically healthy. Changes in device, data source, available records or routine can affect how useful a comparison is.

Stride’s current Apple Health integration reads HRV as SDNN. Fitbit’s HRV commonly uses RMSSD. Those values and their personal baselines stay separate. A difference between the two does not by itself mean that your body changed.

Understand your HRV baseline

Read the coverage with the number.

Missing readings stay missing. Stride does not turn an absent reading into zero or invent a measurement to complete a chart. A score may be unavailable when there is not enough compatible data.

Read the input explanations, available history, coverage and confidence with the estimate. A recent refresh does not guarantee that every measure is up to date. Some sources make different record types available at different times.

On Apple Health, an absent reading does not tell Stride whether permission was denied or the record does not exist. Check the source app and permissions when records appear incomplete.

Understand missing readings

Different views answer different questions.

Sleep

Sleep views explain the recorded night, available stages, patterns and your chosen target. Wearable sleep staging is an estimate and is not the same as a clinical sleep study.

Recovery

Recovery places available HRV and resting heart rate in the context of a personal baseline, alongside sleep context. It is an independent wellness estimate, not a clinical test or permission to ignore symptoms.

Activity and load

Activity views use recorded movement and exercise. Load is derived from available activity records; it is not a complete measurement of everything that made a day demanding.

Physiological stress

Stride uses timestamped heart rate, available HRV and short step intervals to estimate daytime physiological activation. It excludes recorded sleep, exercise, movement and unstable signals. A heart-rate-only estimate is identified when suitable daytime HRV is unavailable. It does not measure hormones, anxiety or psychological stress.

Biological age, experimental

This experimental wearable-based estimate combines available sleep, activity, fitness and lifestyle inputs, with VO₂ optional and minimum data requirements. The supported reference range is ages 20-89. It is not a laboratory measurement, an aging rate, a lifespan prediction or a clinically validated biological-age test. A separate cardio fitness age reference experience answers a different question.

A pattern is a starting point.

Journal associations compare reported habits with next-day recovery when enough observations are present. The app shows uncertainty, because the same pattern can have several explanations.

For example, a reported habit may occur on the same days as a lighter work schedule or a longer night. The association alone cannot identify which influence mattered. It cannot show what would happen if only one thing changed.

Read about habits and recovery

Use the app in its intended role.

Stride is independent wellness software for adults. It does not diagnose conditions, replace professional care or guarantee an improvement in health or performance. Your experience and circumstances remain part of the picture.

The website describes development functionality. Public store downloads are not available yet, and source access depends on the build, permissions and data provided.

For an explanation of storage and account controls, read the Privacy Policy. For a specific connection or reading problem, visit Support.