Recently The New York Times published an article discussing a ‘Recalibrated Formula‘ for female heart rate training. If you have been tuned into the fitness industry, you have probably heard buzzwords like ‘target heart rate’ and ‘zone-training’. Heart-rate training allows you to monitor and regulate the intensity of your workout, ensuring you get the benefits you desire (aka fat-loss, endurance training, power building, etc.) As you know, female bodies are different than males and thus our hearts are different!
The original ‘target-heart rate’ formula is 220 – age. This formula came from research conducted on exercising heart rates of men. Doctors use the formula when they test patients for heart disease, asking them to walk on treadmills while the speed and incline are gradually increased until their HR reach 85% of the predicted maximum (known as the stress test).
After examining 5,500 healthy females, Dr. Martha Gulati from Northwestern Medicine of Chicago presented a revised target-heart rate formula for women. As with many things, the formula is more complicated for women!
206 minus 88 percent of a woman’s age = Target Maximum Heart Rate
The revised heart rate formula for women is an excellent step in the right direction but Gulati et al left out an important part of the equation which is the resting heart rate (RHR). The study calculated heart rate reserve and yet left that important component out of the new equation. (Heart rate reserve is the change in heart rate from maximum exertion to resting)
Gulati herself stated more research needed, but also a closer look at the data is also needed for a better maximum exertion heart rate formula.
Women, its time to do some math!
Understandably most of us will not want to use a longer formula, however without taking RHR into consideration your estimate can be 10-20 beats off. 10-20 beats could mean the difference of burning fat calories and simply burning sugar.
The difference between exhilaration and exhaustion!
As a fitness professional I recommend incorporating resting heart rate as I know that some 40 year olds are triathletes while others flex their biceps only to get their beverage to their mouth. (Their resting heart rates will be different and thus their target heart rates while exercising should reflect that difference!)
Your maximum heart rate is basically fixed, but your resting heart rate is a measure of fitness. The more fit one is, the lower their resting heart rate.
Let’s look at some numbers:
I am a 26 year old female. My Resting Heart Rate is 55.
Target Max Heart Rate: 220 – age = 194 (too high!)
Adjusted Formula for Women: 206 – (age x .88) = 183.12
My actual HR max is 191 but at I try not to exceed 183. Fitness Professionals have been using the Karvonnen Method to calculate target heart rate because it factors in resting heart rate.
Karvonnen Method: ((HRmax – RHR) x %Intensity) + RHR = THR
using 85% intensity and my Resting Heart Rate of 55
(183-55) x .85 + 55 = 163.8
If calculators are not your thing ask a trained fitness professional to assist in finding your estimates.