Your heart rate says a lot about you — it’s a vital clue towards things like your level of fitness, how hard you’re working and how good your overall health is. But if you’re a woman, there’s some bad news — as it turns out, we’ve been using the wrong heart rate formula to calculate our maximum heart rate all this time. The original one is only accurate for men, according to recent scientific studies.
The simple equation — 220 minus your age — helps determine a person’s fastest heart rate in beats per minute. Exercisers around the world have been using it for years to determine how hard to push themselves during a sweat session — usually, people aim to reach about 65 to 85 percent of their maximum heart rate. If someone can’t reach 85 percent in a standardized test for heart disease (called a cardiac stress test,) it typically means they have an increased chance of dying from the disease.
But for women over 35, this isn’t an accurate estimation of her risk of heart disease — in fact, it exaggerates her risk of the disease, giving her a worse prognosis than she actually has. The new proposed formula for women of all ages goes something like this: 206 minus 88 percent of your age. Yep, you’ll need a calculator to figure that one out, but in matters of life and death, it’s worth the extra calculations to get an accurate answer, no?
A stress test that’s specifically designed for women is long overdue, according to the study’s lead author Martha Gulati. “My biggest problem with the literature, particularly with stress testing, is that it’s old information,” she told the Chicago Tribune. “Stress testing was developed in the late ’60s. Should we not as women ask that they study us and use data based on us?”
But it’s not just the women’s formula that’s coming into question — some experts feel that applying a standard measure to all people doesn’t leave room to account for individual differences. “One problem with [the traditional] formula is quite clear: Maximum heart range can vary a great deal,” cardiologist Mike Lauer of the National Heart Lung and Blood Institute told the Chicago Tribune. “It’s very good at describing a phenomenon in a population, but it’s not so good with individual patients. That makes the findings of this study that much more remarkable. [The researchers] found a new formula that, despite the noise, is still a powerful marker for risk.”
Because of these findings, it’s thought that the original heart rate formula could be dropped for both men and women in favor of a new, individualized test, but that’s still a long way off. In the meantime, make sure you have a quality heart rate monitor on hand and know which formula to you should be using to calculate your maximum heart rate.