Apple Watch workout analysis

Workout Strain: the load from this session

Strain is Wellhero's estimate of a workout's cardiovascular load on a scale from 0 to 21. It uses TRIMP, which combines heart rate intensity and duration, with an adjustment for your training background.

The scale is nonlinear. Adding two workout scores will not give the Strain of the combined activity, and a score of 16 does not mean twice the load of 8. Compare sessions alongside their duration, heart rate and Training Load.

The workout score describes this recorded session. The daily Strain in your Today overview includes activity across the day, including activity outside recorded workouts. Keep the session score and the daily total in their respective contexts.

Read the complete Strain guide for the 0–21 scale, daily history, Cardio Load and personal ranges.

In the summary, duration and calories come from the recorded workout. Strain summarizes its load. These fields answer different questions, so sessions with similar calories can have different Strain.

Heart rate: see the shape of the workout

The Heart Rate section shows average and maximum pulse in beats per minute, followed by the recorded timeline. The colors identify heart rate zones; the shaded reference band helps you read the trace against the configured zone boundaries.

Tap or drag across the chart to inspect a point and its time. Check the warm-up, steady sections, intervals and finish. An average can hide short hard efforts that are visible in the timeline.

Missing or sparse readings reduce the detail available for analysis. Use the recording diagnostics further down the report to check how many samples were analyzed and the longest gap between them.

Heart rate zones: where the time went

The zone distribution summarizes time below Zone 1 and in Zones 1 through 5. Read each zone's duration, percentage and displayed pulse boundaries together.

This view helps you distinguish a steady session from one with more time at higher intensity. The timeline shows when those efforts happened; the distribution shows how much recorded time each zone accounts for.

Zone boundaries are part of your heart rate settings. The report's Heart Rate Settings shortcut lets you inspect the limits used by the app. Check those settings when zones seem inconsistent with your recorded pulse.

Training Load: TRIMP, ATL and CTL

TRIMP, or Training Impulse, combines recorded duration and heart rate intensity into one load value. Wellhero uses the Banister method, which weights higher heart rate intensity more heavily.

Fatigue (ATL) is a summary of recent training load using a seven-day time constant. Fitness (CTL) summarizes the longer training background using a 42-day time constant. Both are weighted load estimates that depend on your recorded history.

The report shows the values before and after the workout, with the change alongside them. Read the direction and size of the change over several sessions. ATL and CTL describe recorded load history; they do not measure every aspect of how you feel.

Fresh accounts and incomplete history provide less context for these values. Check data coverage before comparing them with a period that has a fuller recording history.

Use TRIMP to compare recorded sessions

A longer session at lower intensity and a shorter session at higher intensity can produce similar TRIMP. Open the pulse timeline and zone distribution to understand how each session accumulated that load.

Keep the measurement context consistent: recording device, available heart rate data and configured heart rate limits all matter. A gap in the pulse record can change the evidence behind the result.

Tap the question mark beside Training Load to read the method explanation while reviewing your workout.

Training Stress Balance: how the load fits your history

TSB is the difference between CTL and ATL. When recent load rises relative to your longer training background, TSB becomes lower. As recent load eases, the balance can move higher.

The report shows the resulting value, its status, the displayed productive range and the change caused by the workout. In this demonstration, CTL of 29 and ATL of 38 give a TSB of −9.

Read TSB alongside your recent training, recovery readings and how you feel. The label describes the app's load model. A higher value on its own does not establish that you are ready for a hard session.

Read the range shown in your own report

The TSB help screen explains the training-state bands and their boundaries. The ranges shown here belong to the demonstration report; use the values and explanation displayed in your own app.

The app's range interpretation takes training background into account. Thin or missing training history can limit that context, even when a current workout has a detailed pulse recording.

For the relationship between resting pulse and load, read how Wellhero tracks resting heart rate.

Training Focus: the distribution of load

Training Focus divides TRIMP into Low Aerobic, High Aerobic and Anaerobic components. The chart shows how much load accumulated in each category.

These shares describe accumulated load. The heart rate zone chart describes time. A short, intense part of a workout can contribute a larger share of load than its share of the session's duration.

The categories use estimated intensity boundaries derived from heart rate zones. Read them as an interpretation of the recorded session and compare them with the pulse trace and your intended workout.

Heart Rate Recovery: what happened after the finish

When suitable post-workout readings are available, Wellhero shows the recorded pulse across the following minutes and the available recovery measurements.

The two-minute reading is the drop from the pulse at the end of the workout. In this example, pulse falls from 155 to 134 bpm, so the report shows a recovery of 21 bpm. Read the starting pulse and elapsed time alongside the drop.

A long cool-down before stopping the workout can change the starting point. Walking, continuing to exercise and differences in recording coverage also affect the comparison between sessions.

Check the graph and session ending before interpreting the drop. If post-workout samples are missing, this section may be absent. Compare similar finishes and recording conditions over time.

METs: an estimate of activity intensity

A metabolic equivalent, or MET, expresses activity intensity relative to resting energy use. The report plots the available estimates over the session and shows average, beneficial and total summaries.

Average summarizes estimated intensity. Total accumulates intensity over time in MET-minutes: for example, 10 minutes at 6 MET contributes 60 MET-minutes. Beneficial counts the portion accumulated at heart rate Zone 2 or above, which is highlighted in the chart.

Read the timeline to see how intensity varied. Compare the totals alongside duration: a longer session can accumulate more MET-minutes without having a higher average intensity.

These are estimates based on the data available for the workout. Recording gaps and changes in your heart rate settings can affect the analysis.

Fats and Carbs Ratio: estimated fuel use

This section shows an estimated fat-to-carbohydrate ratio over the workout and the available totals in grams. Wellhero derives the estimate from recorded energy expenditure and intensity.

Use it to understand how the app interprets the session's energy demand. Differences in intensity can change the estimated fuel mix even when two workouts have similar calorie totals.

The gram totals are modeled estimates. Their precision depends on the calorie and heart rate data supplied for the session.

Recording quality, heart rate settings and TCX export

Analyzed HR Samples is the number of heart rate readings used for the workout. Max HR Gap is the longest gap between those readings, shown in seconds. Read both fields alongside the pulse chart.

The report also shows the maximum and resting heart rate values used for calculations. Open Heart Rate Settings from this section to inspect your limits.

With PRO, tap Export to TCX to create a workout file and open the iOS share sheet. You can then save the file or upload it to a service that accepts TCX. The export includes the workout information and locally available samples; file acceptance depends on the receiving service.