FullCalculator

Heart Rate Reserve Calculator

Karvonen Method

Formula

THR = ((HRmax − HRrest) × %intensity) + HRrest, where HRmax = 220 − age.

Frequently Asked Questions

What is the Karvonen formula?
The Karvonen formula calculates target heart rate as THR = ((HRmax − HRrest) × intensity%) + HRrest. It uses heart rate reserve (the difference between max and resting HR) for a more individualized training target.
What is heart rate reserve?
Heart rate reserve (HRR) is the difference between your maximum heart rate and your resting heart rate. It represents the range within which your heart can increase its rate during exercise.

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