Karvonen Formula for Heart Rate

The Karvonen formula is a popular mathematical equation that determines exercise heart rate zones. Athletes use these zones to determine how hard they should train on a given day. The zones also determine what body systems are affected during the training and can be used to show training improvement over time.

  1. Why the Karvonen equation?

    • The Karvonen equation was designed to take into account individual variances in physiology and fitness to determine exercise heart rate. It utilizes the patient's max heart rate, resting heart rate, and heart rate reserve (the difference between max and resting HR) to calculate zones instead of taking a fraction of max heart rate as some other equations do.

    The formula

    • The Karvonen formula itself is fairly simple.

      Max heart rate(MHR) - resting heart rate(RHR) = heart rate reserve(HRR)
      (HRR * training%) + RHR = Training target heart rate

      All you need to do is plug in the variables such as Max Heart Rate, Resting Heart Rate and training percentage.

    Filling in the blanks: Max Heart Rate

    • Max Heart Rate can be measured in a number of different ways. The most obvious is to take a max heart rate test at a university or clinic, but this can be both costly and dangerous to undertrained/ untrained people. Fortunately, there is a relatively easy way to calculate max heart rate.

      One method involves subtracting your age from 220 to get max heart rate. This calculation assumes a linear variation between heart rate and age, but the formula overestimates the max heart rate for younger athletes, and underestimates the max heart rate for older athletes.

      A revised formula for max heart rate comes from the journal "Medicine and Science in Sport and Exercise" from May of 2007. The authors believe that this formula results in a more accurate maximum heart rate than the linear 220-age formula. They state that "maximum heart rate = 206.9 - (0.67 x age)."

      The max heart rate number from either formula will give you a max heart rate to plug into the Karvonen formula.

    Filling in the blanks: Resting Heart Rate

    • Resting Heart Rate is very easy to obtain. Simply take your pulse for a full minute the moment after you awaken in the morning. The number of beats per minute will be as close to your true resting heart rate as possible.

    Filling in the blanks: Training Percentage

    • Training percentage is a way to determine what body system will be exercised (recovery systems, aerobic systems or anaerobic systems.) Information on the ranges for these systems and their corresponding values can be found in the resources section of this article.

    Putting it all together

    • By plugging the above values into the Karvonen Formula, athletes can determine how hard they should be exercising in order to build fitness. It is a simple tool that requires little time or money. The formula can be repeated and training zones adjusted as an athlete improves his performance.