Maximum Heart Rate Formula for Women

Trainers, fitness trackers, and cardio machines at the gym will often urge you to determine your maximum heart rate (MHR) to get the most effective workout. For women, it's important to know that the target heart-rate formulas that have been used for decades were derived from research on men.

These formulas appear to overestimate the maximum heart rate for women. A female-specific formula better predicts a woman's maximum heart rate based on her age.

Gender Differences in Maximum Heart Rate

Female and male hearts can differ in mass and size and also display functional and structural differences.

Male hearts grow more rapidly during puberty and on average female hearts are about 26% lighter than male hearts in adulthood. Women also tend to have a higher resting heart rate than men, but their hearts take a longer time from contraction to relaxation.

These differences also affect heart rate responses to exercise. Studies show that heart rate rise during exercise tends to be more rapid in men than women and tracks with standard formulas whereas women's maximum heart rate tends to be lower and recovery takes longer.

The research findings suggest that women might be struggling to reach a certain exercise intensity. Even if she is fit, a woman may find it difficult to achieve a maximum heart rate that has been overestimated.

Research on Maximum Heart Rate Formulas

While investigating how women's heart rates responded to exercise, researcher and cardiologist Martha Gulati and colleagues concluded that "the traditional estimate of the maximum heart rate for age with exercise, based on a male standard, appears to be an overestimate in women."

As a result of these findings, Gulati proposed a female-specific MHR formula in a 2010 study.

In another study published in 2014, a different group of researchers validated Gulati's results. For their study, 19,000 people took a special treadmill test (a highly accurate measure of an individual's maximum heart rate).

The findings suggested that "a separate formula for peak HR in women appears to be appropriate."

Both studies found that the traditional formula used to calculate maximum heart rate (the Fox formula) as well as an updated version that better accounts for age (the Tanaka formula) overestimate maximum heart rate for women.

Formula for Maximum Heart Rate in Women

Researchers wanted to find an accurate peak heart rate for women that could be used to predict their future health.

They also wanted to ensure that women recovering from heart problems were given the right exercise intensity goals while recuperating (given an incorrect result, a woman might put her health in danger by trying to work out too hard).

Comparing Formula Results

Take a look at how target heart rate zones would be different using the female-specific maximum heart rate formula. For example, here are the results for a 49-year-old woman with a resting heart rate (RHR) of 65:

• Fox formula (men and women): 220 - 49 = 171 beats per minute MHR
• Tanaka formula (men and women): 206.9 - (0.67 x 49) = 174 beats per minute MHR
• Gulati formula (women only): 206 - (0.88 x 49) = 163 beats per minute MHR

There are also other factors. If you derive target heart zones using the Karvonen formula (which accounts for resting heart rate) you'll get a different result.

For a suggested exercise zone between 65% and 85% maximum, you can see how different the ranges are:

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

Formula Limitations and Alternative Approaches

Keep in mind that these formulas are based on population statistics. An individual woman's actual maximum heart rate can vary significantly from one provided by these formulas.

The only way to know your maximum heart rate is to have it measured on a maximal treadmill test.

However, unless you're an elite athlete or a cardiac patient, you might not need to pinpoint your target heart rate when you exercise—following the scale of perceived exertion might be all you need.

Bottom Line

If you are a woman and you want to get the best information about your target heart rate, use the Gulati formula combined with the Karvonen formula.

Even the best formula can only make an estimate of your maximum heart rate. This is another reason the perceived exertion scale is the most practical way to estimate how hard you are working during exercise.