A new study says that differences between men and women are not considered in the formula doctors use to evaluate treadmill stress test and heart health.
The researchers said that an updated formula is more capable of measuring peak exercise rate, which is the maximum amount of heart beats per minute, according to CBS News.
"Exercise physiology has been known to differ for men and women of different ages," said Dr. Gregg Fonarow, associate chief of cardiology at the University of California, Los Angeles, and spokesman for the American Heart Association.
The current formula that doctors use is "200 minus age", which determines how hard patients should work out in exercise stress tests, WebMD reported. Some people use this formula during their workouts to set their target heart rate.
Dr. Thomas Allison, director of stress testing at the Mayo Clinic in Rochester, Minn., led a team that reviewed 250,000 stress-test results. The team found noticeable differences between men and women, such as while peak heart rate decreases with age for both sexes, the rate goes down more gradually for women. The researchers said the difference has led to overestimated peak heart rate for younger women and underestimated peak heart rate for older women, WebMD reported.
The study authors developed a new formula based on the data they found, CBS News reported. In the updated formula, the maximum heart rate for women from age 40 to 89 should be 200 minus 67 percent of their age. For men, the formula should be 216 minus 93 percent of their age. The researchers couldn't recommend a new formula for women under 40 due to limited test results.
"We want to make sure that when people do the stress test, they have an accurate expectation of what a normal peak heart rate is," Allison said.
They discovered that younger men have a lower resting heart rate and higher peak heart rate than women. Researchers said they also found that men's heart rates increase more dramatically during exercise and return to normal faster after stopping, CBS News reported.
The study did not look at reasons for the difference in genders, but the researchers guessed that hormones, especially the male hormone testosterone, may have played a role, according to WebMD.
The research will be presented in Washington, D.C. on Saturday at the annual meeting of the American College of Cardiology.
