Why Women Need a Female-Specific Maximum Heart Rate Formula

Female-Specific Formula Proposed by Researchers

Mature women jogging in park, checking heart rate monitor wrist watch
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The traditional heart rate formulas used to calculate maximum heart rate (MHR) appear to overestimate maximum heart rate for women. Research shows a female-specific formula better predicts a woman's maximum heart rate based on her age. It's taken the medical and fitness world some time to figure out that women aren't just small men, but they are getting there.

Age-Based Maximum Heart Rate Formulas

A female maximum heart rate formula was first proposed by researcher Martha Gulati based on data from the St. James Women Take Heart Project in 2002. Further validation has been made by researchers who looked at over 19,000 subjects who took a Bruce protocol treadmill test, which is a highly accurate test for an individual's maximum heart rate. These and other studies showed that the traditional Fox formula used to calculate maximum heart rate, (220 minus age), or the updated Tanaka version (206.9 minus (0.67 * age)) overestimate maximum heart rate for women.

With this information, experts have come up with a new formula to calculate maximum heart rate for women. 206 minus (0.88 * age) = MHR

The researchers of the St. James study were interested in finding an accurate peak heart rate for women in order to predict future health and to make sure women recovering from heart problems were given the right exercise intensity to recuperate.

If the numbers were too high, they might be doing women more harm than good by trying to make them work too hard.

Example of Three Maximum Heart Rate Formulas

Take a look at how target heart rate zones would be different using the new maximum heart rate formula when used with the Karvonen formula. Say you're a 49-year-old woman with a resting heart rate (RHR) of 65:

  • Fox Formula (Men and Women): 220 - 49 = 171 beats per minute maximum heart rate
  • Tanaka Formula (Men and Women): 206.9 - (0.67 * 49) = 174 beats per minute maximum heart rate
  • Gulati Formula (Women Only): 206 - (0.88 * 49) = 163 beats per minute maximum heart rate

If you derive target heart zones using the Karvonen formula, which accounts for resting heart rate, you get very different results. For a suggested exercise zone between 65 percent and 85 percent maximum, you get these ranges:

  • Fox Formula: 133 to 155 beats per minute
  • Tanaka Formula: 136 to 158 beats per minute
  • Gulati Formula: 129 to 148 beats per minute

You can see how different these numbers are and this suggests that some women may be struggling to get to a certain intensity. They may be fit, but their maximum heart rate has been overestimated.

While the CDC still shows the Fox formula on its website for estimating maximum heart rate, that may change in coming years to provide a more accurate result for women.

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