Maximum Heart Rate - Understanding Your Maximum Heart Rate

Man checking heart rate on phone
Man checking heart rate on phone. Hero Images/Getty Images

If you've spent any time exercising, you probably know all about working in your target heart rate zone to burn the most calories and get the most out of your workout time.

A big part of that calculation involves your maximum heart rate (MHR). Your MHR refers to the fastest rate at which your heart will be in one minute.

Okay, that makes sense, but why do you need to know this number? If you're using a heart rate monitor to track your intensity, you definitely need your MHR.

The important thing to note is that, unless you're in a laboratory setting where they can hook you up to machines, it's tough to get pinpoint accuracy of your MHR.

So, we do the next best thing which is to make an informed guess.

For many years, the typical formula for calculating your maximum heart rate was: 220-age. Eventually, experts realized there's a big problem with that particular formula. It doesn't reflect the differences in heart rate according to age.

You may not be aware of this, but MHR actually decreases as we age. One reason is that one of the reasons is the getting older actually depresses the sinoatrial node, the natural pacemaker for the heart. 

That's something the old formula doesn't take into account. In fact, there's some suggestion that using that formula to calculate heart rate could give you numbers that are way off, maybe by as much as 12 beats per minute up or down.

That's a huge gap.

Luckily, experts have come up with a more accurate formula, offered in a study published in Journal, Medicine & Science in Sports & Exercise.

Your Maximum Heart Rate Formula:

206.9 - (0.67 x age)

Facts About Your Maximum Heart Rate

  • Your MHR is determined by your genes.
  • MHR is usually higher in smaller people, which is why women often have a higher MHR than men.
  • Altitude can lower your MHR.
  • MHR has nothing to do with how fit you are and doesn't reflect your level of fitness.
  • Your MHR can decline as you age or if you become unfit.
  • MHR can vary significantly even among people of the same age and gender.
  • Training doesn't really change your MHR and, if there is any change, it may get lower as your body experiences expanded blood and stroke volumes.

Figure Out Your Exercise Intensity Using MHR

If you use the calculation above, you come up with a number that equals that max amount of beats your heart will beat in one minute.

Using that information, you can actually figure out how hard to work during exercise based on your level of fitness.

  • If you're very sedentary with no exercise at all, you should work at about 57-67 percent of your MHR.
  • If you engage in minimal activity, you should work at 64-74 percent of your MHR.
  • If you sporadically exercise, you should work at 74-84 percent of your MHR.
  • If you regularly exercise, you should work at 80-91 percent of your MHR.
  • If you exercise a lot at high intensities, you should work at 84-94percent of your MHR.

Example

Below is an example of how to use the formula to calculate a maximum heart rate for someone who is 45 years old:

(206.9) - (0.67 x 45) = 176 beats per minute. 

Now, to actually use that to figure out how hard to work. Say you're a sporadic exerciser, so you're shooting for about 74 percent and up to 84 percent of your max heart rate which, if you're 45, is 176 beats per minute.

That means you would have a heart rate zone of 130 beats per minute at the lower end and up to 148 beats per minute at the higher end.

That's just a general guideline to follow and the best way to get more specific with these numbers is to note how hard you're working at different levels of intensity, or your Perceived Exertion.

This Perceived Exertion Chart gives you a 1 to 10 scale to use to mentally determine how you feel at different intensities.

Say you're working at 148 beats per minute. You might match that to a level on the perceived exertion scale.

As you practice doing that, you'll get a better idea of what you can handle and when you need to speed up or slow down.

Source:

Jackson, Andrew S. Estimating Maximum Heart Rate From Age: Is It a Linear Relationship? Med Sci Sports Exerc. 39(5):821, May 2007.

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