How to Read Heart-Rate Zones in Zolt

What heart-rate zones represent, which settings shape them, and how to troubleshoot zones that do not match your workout.

ActivityVitalsUpdated 2026-08-22
Zolt showing time spent in heart-rate zones during activity

Heart-rate zones divide a workout into intensity bands. Zolt uses them to show how the effort was distributed, so you can distinguish easier work from harder work without reading every heart-rate sample.

What the five zones mean

The labels run from lower to higher intensity:

ZonePractical reading
Zone 1Very easy effort
Zone 2Easy aerobic effort
Zone 3Moderate effort
Zone 4Hard effort
Zone 5Very hard effort

These are descriptive bands, not medical boundaries. The same heart rate can feel different across people and activities.

What shapes your zones

Your zone settings depend on the heart-rate information in your profile, including resting and maximum heart rate where available. Estimated values are starting points. If you have professionally measured values or established training zones, use the editable settings provided in Zolt.

The app groups your recorded workout heart rate using your current settings and shows the time in each band.

How to use the view

  • Check whether an easy session stayed mostly in the lower zones.
  • Check whether hard intervals appear in the higher zones.
  • Compare similar workouts over time.
  • Read zone time with duration and perceived effort.

Do not assume that more time in a higher zone is always better. The right distribution depends on the session, your training plan, your health, and your experience.

If the zones look wrong

  1. Check the workout's heart-rate record in the source platform.
  2. Review your resting and maximum heart-rate settings.
  3. Confirm that the correct workout and device supplied the data.
  4. Look for sensor gaps or implausible spikes.
  5. Compare the result with your perceived effort.

A field test for maximum heart rate can be physically demanding and is not appropriate for everyone. Seek qualified guidance before attempting one if you have a medical condition, symptoms, or uncertainty about vigorous exercise.

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