Target heart rates should be recalculated, cardiologist says

Exercise intensity should be high enough to help your health but not so high it endangers your health.

Widely accepted standard calculations used over the past 40 years were based on male-only studies.

But "women are not small men," Gulati says. Women have a different exercise capacity that should be measured using a gender-specific formula.

Gulati developed one in 2010 based on a study of 5,437 healthy Chicago-area women ages 30 and older. It tells women to take 88 percent of their age and subtract it from 206 to find their maximum heart rate.

Using the right calculation makes a big difference, explains Julie Ramos, a cardiologist at Montefiore Medical Center in New York City.

At the gym, target heart rates help determine how hard you need to exercise to achieve an aerobic workout or stay in the fat-burning zone.

In the doctor's office, it shows that women who can't reach the old target heart rate are not at as high a risk for cardiac events and death as men who can't reach their targets.

But some fitness experts don't think the new formula is much of a game-changer.

Asked what the new rate means when women go to the gym, Carl Foster, former president of the American College of Sports Medicine, said, "Absolutely nothing."

The old formula (220 minus age) was "an average of averages," Foster explains. Everyone knew it was not very good, but it was a starting point.

And it did offer "a very quick way for us to get in the ballpark," says Walter Thompson, a Georgia State University regents' professor in kinesiology and health and the senior editor of the ACSM's Guidelines for Exercise Testing and Prescription, 8th Edition.

Missouri State University professor Barbara Bushman, who is also an ACSM spokeswoman, allows that target heart rate formulas can be useful but says two other tests are better.

You assess how hard you're working based on how you feel in the perceived exertion test. "Moderate" is good. Unless you're an athlete, make "sort of hard" your upper limit, Foster advises.

Your breathing is the telltale clue in the talk test. Ideally, you should be able to speak in complete sentences without breathing hard.

At the right intensity, Bushman says you should be able to talk comfortably but not sing.

Women who can't reach their target heart rate using the old formula should talk to their doctors about the new rates for women. But don't assume the doctor knows about this, Ramos cautions.

"Most practitioners may not even be aware of the new studies."

Dig out your calculator. Though "206 minus 88 percent of your age" may not be as simple to use as the old formula, Gulati says you need only to use your calculator to figure it out on your birthday.

Soon she hopes to have an iPhone app that will make calculating women's target heart rates easy and fast.

(c)2011
Distributed by MCT Information Services