New Peak Heart Rate for Women Suggested

(June 30, 2010) - A new study says that men and women are different, especially when it comes to their hearts. A new formula that estimates the peak heart rate a healthy woman should attain during exercise testing more accurately predicts the risk of heart-related death, according to research reported in Circulation: Journal of the American Heart Association. (Read about "Target Heart Rate" "Heart Risks")

For nearly four decades, physicians have used a simple formula - 220 minus age - to estimate peak heart rates for women and men during exercise. However, the formula was derived from studies of men. The formula applied to women in the new study is 206 minus 88 percent of age.

"Using the standard calculation, we are more likely to tell women they have a worse prognosis than they do," said Martha Gulati, M.D., lead author of the study. "With this gender-specific formula, our risk predictions in women will be more accurate."

At age 50, the original formula gives a peak rate of 170 beats per minute for men and women. The new formula yields a maximal heart rate of 162 beats for women. Many men and women use their peak heart rate multiplied by 65 percent - 85 percent to determine their upper heart rate when exercising.

The traditional formula has proven accurate for projecting the risk of dying prematurely from heart disease for a man who fails to attain at least 85 percent of his estimated peak heart rate during treadmill or stationary-bicycle testing. However, these findings demonstrate the inadequacy of that formula in women.

"Women are not small men," Gulati said. "There is a physiologic response in women that is different from men."

The new formula is from an analysis of 5,437 healthy women age 35 and older. Their average age was 52.

The American Heart Association and other groups have not taken a position on this new suggested heart rate formula for women.