How heart rate zones are calculated
The Karvonen method uses your heart rate reserve, the gap between resting and maximum, so the zones fit your fitness level better.
Example: a 40-year-old has an estimated max of 180 bpm (both formulas agree at this age). With a resting heart rate of 60, the reserve is 120, so zone 2 at 60% to 70% is 132 to 144 bpm.
Using your zones
- Zone 2 is where most endurance training happens: you can talk in full sentences. Many plans put about 80% of training here.
- Zones 4 and 5 build speed and power but need recovery; keep them to short intervals.
- The AHA's general target for moderate exercise is 50% to 70% of max, and 70% to 85% for vigorous exercise.
- Some medications, such as beta blockers, lower heart rate. Ask your doctor about targets if you take them or have a heart condition.
Track your runs with the pace calculator.
Frequently asked questions
What is zone 2 heart rate?
About 60% to 70% of your maximum, or of your heart rate reserve using Karvonen. For a 40-year-old with a resting heart rate of 60, that's roughly 132 to 144 bpm.
Is 220 minus age accurate?
It's a population average with a wide spread: real maximums vary by 10 bpm or more. The Tanaka formula is a bit more accurate for older adults. A supervised max test is the most accurate.
What is a good resting heart rate?
60 to 100 bpm is normal for adults; well-trained athletes are often in the 40s or 50s.
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