Heart rate zones turn a workout number into a useful question: how hard are you working, and does that effort match today’s goal? Whether you run on roads, explore trails or hike uphill, understanding your zones can help you pace yourself and make better sense of your sports watch.
This guide explains a common five-zone system, why Zone 2 numbers differ between apps, and how to use a target heart rate calculator without treating its result as a personal prescription.
A zone is a range of heart rates used to describe exercise intensity. The table below uses percentages of maximum heart rate (%HRmax). It is an illustrative five-zone convention, not the only system. Percentage boundaries do not identify your individual physiological thresholds.
| Zone | % of maximum heart rate | Typical purpose |
|---|---|---|
| 1 | 50–60% | Very easy movement and warm-up |
| 2 | 60–70% | Easy aerobic work |
| 3 | 70–80% | Steadier, more demanding aerobic work |
| 4 | 80–90% | Hard training |
| 5 | 90–100% | Very hard efforts, held briefly |
These labels describe a training model. Your body uses overlapping energy systems throughout exercise; it does not flip from purely aerobic to purely anaerobic at a particular watch reading.
In the table above, Zone 2 means 60–70% of maximum heart rate. In other coaching systems, “Zone 2” describes an intensity anchored to a physiological threshold rather than this fixed percentage. Check the definition in the plan you follow before copying a target from another runner.
For an easy outing, conversation and perceived effort provide useful context. The CDC describes moderate activity as an effort where you can talk but not sing. This talk test is not a laboratory threshold test, and its categories do not map exactly onto every five-zone chart.
Calling a zone the “fat-burning zone” can be misleading. The proportion of fuel coming from fat is different from total energy expenditure or long-term fat loss. Choose the intensity that fits your training plan rather than assuming one heart rate guarantees a body-composition result.
Multiply your maximum heart rate by the lower and upper percentages of the chosen zone. If maximum heart rate is 180 bpm, the 60–70% band is 108–126 bpm. This is a worked example, not a target for everyone.
The familiar 220 minus age formula gives a rough population-based estimate of maximum heart rate. Individual values can differ substantially. If you have an appropriately established maximum, use it instead of assuming an age formula is exact. Do not attempt an all-out test just to configure a watch.
Heart rate reserve is maximum heart rate minus resting heart rate. The calculation is:
Target HR = resting HR + intensity × (maximum HR − resting HR).
For maximum HR of 180 and resting HR of 60, a 60–70% reserve band is 132–144 bpm. Notice that this differs from 108–126 bpm above. The same percentages under different methods do not represent interchangeable targets. Use the method and boundaries specified by your plan.
Some plans use lactate-threshold heart rate or laboratory thresholds. These require a different set of boundaries. A generic age-based calculator cannot locate those thresholds for you.
The existing Omni calculator is retained below. Check its displayed method and inputs before interpreting the result. A calculator that asks for resting heart rate may use heart rate reserve rather than a simple percentage of maximum. Do not compare its output with the table above unless the methods match.
If the embedded tool does not load, open the target heart rate calculator. Results are estimates for general education, not medical clearance or a diagnosis.
| Zone | Range (beats per minute) | Intensity (%HRmax) | General description |
|---|
Zones depend on the method and the boundaries chosen. The same percentages in the two methods are not the same training targets: 70% of max HR and 70% of heart rate reserve give different numbers. These boundaries are general guides and do not identify your personal physiological thresholds, so perceived effort and the talk test still matter. This is not medical advice; if you have a medical condition or concerns, check with your doctor.
Use the free Mountainotes Interval Timer for run/walk sessions or planned work and recovery intervals. Set your warm-up, rounds and cool-down, then bookmark your session with Copy share link. The timer’s optional intensity labels use %HRmax; they are not interchangeable with %HRR targets and do not measure your heart rate.
For related guidance, read our VO₂ max guide, half-marathon training and training for hiking and trekking.
Start with the information you need. Compare comfort, sensor fit, compatibility with your watch or phone, battery requirements and the ability to review a workout. Check whether the watch lets you choose %HRmax, %HRR or threshold-based zones. Device support varies, so confirm the exact model’s manual before buying.
Before shopping: make a shortlist of the features you will actually use, then check compatibility and current specifications. A higher price does not remove the need to configure your zones correctly.
They may use different maximum heart rates, resting heart rates, zone boundaries or calculation methods. Compare those settings before deciding which number to follow.
No. You can begin by using perceived effort and the talk test. A monitor adds information; it does not replace awareness of your body or surroundings.
A complete plan depends on your experience and goals. Avoid copying another person’s zone distribution without considering their training history and the definition of the zones.
Some medicines and health conditions change the response to exercise. Ask your healthcare professional for suitable intensity guidance. Stop exercising and seek urgent help for chest pain, fainting or severe unusual breathlessness.
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