New formula for women's peak heart rate

CHICAGO, June 28 (UPI) -- Women have a new way to calculate peak heart rates during exercise, which is easier to attain but harder to calculate, U.S. researchers said.

Dr. Martha Gulati of Northwestern Medicine and colleagues say the new calculation provides a more accurate estimate of the peak heart rate a healthy woman should attain during exercise.

The old formula -- 220 minus age -- is based on studies of men but the new formula for women is 206 minus 88 percent of age.

For example, the original formula calls for a woman at age 50 to have peak rate of 170 beats per minute for men and women.

However, the new formula for women -- based on a study of 5,437 healthy women age 35 and older -- gives a maximum heart rate of 162 beats for women.

"Now we know for the first time what is normal for women, and it's a lower peak heart rate than for men," Dr. Martha Gulati, a cardiologist at Northwestern Medicine, says in a statement. "Before, many women couldn't meet their target heart rate. Now, with the new formula, they are actually meeting their age-defined heart rate."

Gulati acknowledged the new formula is trickier to calculate but she is currently is working on an iPhone application for a quick calculation.

The study is scheduled to be published in the journal Circulation.