Heart rate zones calculator for running
Calculate your 5 heart rate zones to structure your running training. Pick the Karvonen method (more accurate) or the % of Max HR method (simpler).
Calculate your HR zones
Ideally measured via a field test or stress test.
Understanding heart rate zones
Heart rate zones split training intensity into 5 ranges. Each zone targets a different physiological effect: recovery, endurance, tempo, threshold, or maximum power. Combined with your MAS and your training paces, they help you progress faster while avoiding overtraining.
Warm-up, cool-down, active recovery.
Easy aerobic base, long runs, foundation work.
Active endurance, marathon pace, aerobic threshold.
Hard sustained effort, lactate threshold, long intervals.
Maximum effort, short intervals, aerobic power.
Karvonen method vs. % of Max HR
Karvonen method
Uses heart rate reserve (Max HR minus Resting HR). More personal, it accounts for your resting fitness. Recommended for regular runners who know their resting HR.
Formula: target HR = (HRR × intensity %) + Resting HR
% of Max HR
Applies a simple percentage to your Max HR. Easier to use if you don't know your resting HR. Less precise for very well-trained athletes.
Formula: target HR = Max HR × intensity %
How to find your Max HR
Three options, by order of accuracy.
1. Lab stress test (most accurate)
Performed on a treadmill or bike with progressive load until exhaustion. Gives you Max HR within 1 to 2 bpm. Costs 100 to 200 EUR / USD typically.
2. Supervised field test (good)
Run an all-out maximum effort, e.g. a 2km MAS test, after a thorough warm-up. Wear a chest-strap monitor (more accurate than a wrist sensor at high HR). The peak value is a good Max HR estimate.
3. Age formula (rough estimate)
The classic 220 minus age has a standard deviation of 10 to 12 bpm. The Tanaka formula (208 minus 0.7 × age) is slightly better. Use only as a fallback.
Frequently asked questions
How do you find your maximum heart rate?
The most reliable way is a lab stress test or a supervised field test (e.g. an all-out MAS test). The 220 minus age formula is rough and can be off by 10 to 20 bpm: it's not recommended for personalised training.
What is the Karvonen method?
The Karvonen method uses your heart rate reserve (Max HR minus Resting HR) to calculate zones. It is more accurate because it accounts for your resting fitness level. Recommended for trained runners who know their resting heart rate.
How do you measure your resting heart rate?
Take your pulse first thing in the morning, lying in bed, for 60 seconds. Repeat over 3 to 5 days and average the values. A wrist-based heart rate monitor will also give you this data automatically.
Why train by heart rate zones?
HR zones let you dose the intensity of every session. They prevent the classic 'always too fast' trap and make sure your easy days stay easy and your hard days stay hard.
What is the difference between % of Max HR and the Karvonen method?
% of Max HR is simple but less personal. Karvonen factors in your resting HR, which produces zones better tailored to you, especially if you have a low resting HR (well-trained athlete) or a high one (beginner).
How accurate is the 220 minus age formula?
It is a population average with a standard deviation of about 10 to 12 bpm, meaning your true Max HR can be 20 bpm above or below the formula. Use it only as a starting point if you have no measured value.
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Calibrate your HR zones and let Kopilo pilot the intensity of every session.