The traditional heart rate formulas used to calculate maximum heart rate (MHR) purportedly overestimate MHR figures for women. Research shows that a female-specific formula could better predict a woman’s MHR based on her age. Until now, the majority of calculations apply the same formulas for men and women, but there is increasing consensus that women and men need to be treated differently in this respect.
Age-Based Maximum Heart Rate Formulas
A female-specific 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 MHR. These and other studies showed that the traditional Fox formula used to calculate MHR, (220 minus age), or the updated Tanaka version (206.9 minus (0.67 * age)) overestimate MHR for women.
With this information, experts have come up with a new formula to calculate MHR 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 during exercise.
Maximum Heart Rate Formulas
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 * 49) = 174 beats per minute MHR rate
- Gulati Formula (Women Only): 206 – (0.88 * 49) = 163 beats per minute MHR
If one derives target heart zones using the Karvonen formula, which accounts for resting heart rate, one gets very different results using the above 3 MHR calculations. As an example, for a suggested exercise zone between 65 percent and 85 percent of MHR, here are the formulated 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
We can see wide a variance there are within these intensity ranges, which could suggest that some women may be struggling or working too hard to reach a certain training intensity.
More research will hopefully be conducted on this important topic in coming years.
Article Credit – Paige Waehner, www.verywellfit.com