Why the Karvonen method is used
A simple "percentage of maximum heart rate" approach ignores how fit you already are. The Karvonen method is more personal because it works from your heart-rate reserve, the gap between your maximum and resting heart rates, and then adds your resting rate back in.
Maximum heart rate here is estimated as 220 minus your age. Multiplying the reserve by your chosen intensity and adding your resting rate gives a target in beats per minute that reflects your own baseline fitness.
Choosing your intensity
Different efforts produce different training effects, and the right zone depends on your goal.
- About 50 to 60 percent: easy warm-up and recovery pace.
- About 60 to 70 percent: builds aerobic base and endurance.
- About 70 to 80 percent: improves cardiovascular fitness and stamina.
- About 80 to 90 percent: hard intervals that raise your performance ceiling.
Reading the chart
The bar chart compares your lower and upper target heart rates against your estimated maximum, so you can see where your training zone sits relative to your ceiling.
For the most useful numbers, measure your resting heart rate first thing in the morning. If you know your true maximum from testing, your real zone may differ from the age-based estimate.
A note on health
These zones are general guidance, not medical advice. The 220 − age formula is only an average and can be off for an individual. If you take heart medication, have a cardiac condition, or are new to vigorous exercise, talk to a doctor before training at high intensities.
Formula
maxHR = 220 − age; target = (maxHR − restingHR) × intensity% + restingHRFrequently asked questions
- What intensity should I train at?
- Moderate aerobic exercise is roughly 50 to 70% of heart-rate reserve, while vigorous training sits around 70 to 85%. The defaults of 50 and 85% cover a broad fat-burning to cardio range.