Published on August 08, 2026 • Last updated August 08, 2026
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A target heart rate zone is a personalized range of heartbeats per minute that corresponds to a desired training intensity, calculated from an estimated maximum heart rate and, in more precise methods, resting heart rate.
Training at the right intensity is easier to manage with a concrete number to aim for, which is what a target heart rate zone provides. It starts with estimating Maximum Heart Rate (MHR) — most simply with the traditional "220 minus age" formula, or with the more research-validated Tanaka formula ("208 minus 0.7 times age"), which tends to be considered more accurate, especially for older adults. From there, a percentage of that maximum can define broad intensity zones — light, moderate, or vigorous activity.
A more personalized approach, the Karvonen method, factors in resting heart rate as well, using something called Heart Rate Reserve (the gap between max and resting heart rate) to calculate a target zone that better reflects individual fitness levels. Two people of the same age can have very different resting heart rates depending on their cardiovascular fitness, and the Karvonen method accounts for that difference rather than applying a flat percentage of age-based maximum heart rate to everyone equally. Target heart rate zones are widely used in structured cardio and endurance training to ensure a workout is neither too easy to produce fitness gains nor so intense that it risks overtraining or injury.
They're commonly divided into zones such as fat-burning, aerobic/endurance, and high-intensity/anaerobic, each associated with a different percentage range of heart rate reserve or maximum heart rate, and each suited to different training goals.
Learn how Target Heart Rate Zone is calculated
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