Max Heart Rate Is Key to Your Fitness Results: Here's How to Find It

Max Heart Rate Is Key to Your Fitness Results: Here's How to Find It

“Maximum heart rate” sounds like a terrifying concept (what happens if it goes any faster??), but it’s not like a warning light on your dashboard. Knowing your MHR can be beneficial to ensuring ongoing progress towards your fitness goals. Here’s what max heart rate is, and how to use that number to help you get fitter, faster.

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What Is Maximum Heart Rate?

Measured in beats per minute, maximum heart rate is the fastest rate at which your heart can beat. Sound simple? “There are a lot of misconceptions about max heart rate,” says Openfit Director of Fitness and Nutrition Content Trevor Thieme, C.S.C.S. “You can’t increase it, for example, but it does decrease with age,” regardless of how hard or consistently you exercise.

Maximum heart rate is not a measure of fitness, though your capacity for sustained exercise at a high percentage of your MHR is. Maximum heart rate is also affected by altitude, says Thieme (the higher you climb, the lower your MHR) and body size (the smaller you are, the higher your MHR).

 

Why Should I Know My Maximum Heart Rate?

person checking their heartrate on smart watch | max heart rate

Knowing your max heart rate allows you to customize your workouts to help you reach a variety of fitness goals. To build cardiovascular endurance and overall aerobic fitness, for example — the ability to perform low- to moderate-intensity work for long periods — you’ll work at a lower percentage of your MHR than if you’re trying to build strength, power, speed, and muscular endurance.

So having at least a rough estimate of your MHR can help you build an exercise routine tailored to your objectives, with no time or workouts wasted. (See the chart below for a breakdown of the effects of training in different heart rate “zones.”)

Fitness Goal Percentage of Maximum Heart Rate
Recovery <65%
Cardiovascular Endurance 65% – 75%
Muscular Endurance 75% – 80%
Speed & Power 80% – 90%

 

What’s the Best Way to Calculate Max Heart Rate?

The most accurate way to calculate MHR is in a lab using sophisticated equipment. But assuming you don’t have easy access to such gadgetry, there are several formulas you can use to calculate it.

1. Use an age-based formula

The simplest and fastest way to estimate your maximum heart rate is using an age-adjusted formula. One such formula — known as the Gelish formula — is as follows:

      207 – (0.7 x AGE)

So if you’re 50 years old, you’d multiply 50 x 0.7 to get 35, then subtract that number from 207 to get 172. That’s your MHR.

This is a variation on the “220-minus-AGE” formula you’ve probably heard recommended by trainers and seen printed on treadmills, bikes, and elliptical machines in gyms the world over since time immemorial.

In fact, 220-minus-AGE is based on data collected and analyzed by Drs. William Haskell and Samuel Fox in the 1970s. Despite its popularity, the formula can be inaccurate for many people. Haskell himself has denied that the formula was ever intended as a hard-and-fast rule to govern cardiovascular conditioning for all populations.

Given the unreliability of this well-worn formula, many researchers have since come up with age-based formulas of their own. They include:

  • The Gelish Formula: 207 – (0.7 x AGE)
  • The Tanaka Formula: 206.9 – (0.67 x AGE)
  • The Hunt Formula: 211 – (0.64 x AGE)
  • The Inbar Formula (205.8 – 0.685 x AGE)

Each formula, naturally, yields a slightly different estimate for max heart rate. Using these formulas, a 48-year-old exerciser, for instance, will get results ranging from 172 beats per minute (using 220-minus-AGE) to 180 beats per minute (using the Hunt formula). A 25-year old will see results from 189 BPM (Inbar) to 195 BPM (220-minus-AGE).

According to a 2002 review, the age-based formula with the narrowest range of uncertainty is Inbar: 205.8 – (0.685 x age), rounded to the nearest whole number.

Short of testing, we recommend using that formula to estimate max heart rate.

 

2. Use a formula based on age and sex

In 2010, Dr. Martha Gulati, working off of data from over 5,000 women, proposed a different max heart rate specifically designed for women:

  • Multiply your age by .88 (i.e. 88 percent of your age).
  • Subtract that number from 206

Gulati’s results are typically slightly lower than other age-based formulas. So if you’re a 55-year-old woman, you can find your MHR by multiplying .88 by 55 and subtracting the result from 206. That gives you an MHR of 157.6, which you would round up to 158.

Like the age-based formula, this one works fine, but still suffers a broad range of uncertainty: MHR can vary widely, based not on fitness, but primarily on genetics. So some fit people tire quickly at a low percentage of their age-based MHR; others the same age may feel very little at that percentage. If you’re female, use either the Inbar formula or the Gulati formula.

 

3. Use the heart rate reserve (HRR) formula

While not technically a measure of max heart rate, another formula you can use to determine training intensity is the Karvonen method, or heart rate reserve formula. Your heart rate reserve is a measure of the difference between your maximum heart rate and your resting heart rate (RHR) — in other words, the range of speeds at which your heart is capable of contracting. Since HRR factors in your resting heart rate — a loose measure of your current level of cardiovascular fitness — it’s a good one to use if you’re training consistently and seeking higher levels of cardiovascular fitness.

To calculate training intensity using HRR, follow these steps:

First, measure your resting heart rate:

  • Gently place your fingertips on one side of your windpipe until you find a pulse.
  • Count your heartbeats for 30 seconds and multiply the result by 2 to calculate beats per minute (BPM).
  • For a more accurate reading, measure your RHR first thing in the morning, before getting out of bed.

Second, find your heart rate reserve:

  • Subtract your RHR from your MHR. Men should use the Inbar formula (205.8 – [0.685 x AGE]) for this; women can use either Inbar or the Gulati formula (206 – [.88 x AGE]).

So, a 30-year-old man with a resting heart rate of 60 BPM would subtract his age x 0.685 from 205.8 to get an MHR of 185, then subtract his resting heart rate to get 125.

Third, determine your exercise intensity:

  • Use the chart above to determine the appropriate heart rate percentage for your fitness goal.
  • Multiply the desired heart rate percentage by your heart rate reserve (HRR).
  • Add your resting heart rate.

So, a 25-year-old woman with a resting heart rate of 55 BPM who wanted to work out at 75 percent intensity would find her HRR by multiplying 25 by .88 and subtracting the result (22) from 206 to get 184. She would then subtract her RHR to get 129.

Then she would multiply that HRR (129) by the desired percentage (.75) to get 97, then add back her RHR: 97 + 55 = 152. That number represents 75 percent of this exerciser’s maximum intensity.

HRR is the most math-heavy formula of the bunch. And because your resting heart rate changes over time, it also requires you to re-calculate heart rate reserve periodically. However, since the HRR formula can factor in age, sex, and fitness level, it’s the best one to use short of an individualized test.

 

4. Find your active training heart rate

The final, and most accurate, method for determining training heart rate requires a wearable heart rate monitor. Instead of using a passive, catch-all formula, “Ride or run a 30-minute time trial [going as far and as fast as you can] with no stops,” suggests endurance coach Gareth Thomas (FFI/ NCF/ RAW/ ITEC). “Look to cover as much distance you can,” then make the following calculations:

  • Record your average heart rate for the last 10 minutes of effort.
  • Multiply this number by 95 percent to get your “functional threshold heart rate.” This is the highest intensity you can sustain for more than a few minutes, and therefore will be lower than your MHR, which is the maximum speed your heart is capable of beating.
  • Input this number into the formulas that come with your smartwatch or heart rate monitor to calculate your training zones.

If you want to maximize your performance — usually for endurance racing — this kind of road testing works best. Says Thomas, “This allows you to avoid the flawed maxHR theory, and will give you a far more accurate basis for your ongoing training.” For day-to-day workouts, however, the paper-and-pen formulas work fine.

 

Road-Test Your Numbers

female runner checking heartrate monitor | max heart rate

A max-heart-rate formula isn’t much good until you’ve applied it in your workouts. So whichever formula you choose (we recommend the heart-rate reserve formula), you’ll eventually need to try it out see how it works in practice.

To refine your numbers, strap on a heart rate monitor and go for a workout or two. Does the “recovery zone” feel comfortable at the heart rate you calculated for it? Does the “speed and power” zone feel close to your top effort? If not, re-toggle your estimated MHR up or down by 5 to 10 points to match the appropriate rate of perceived exertion and recalculate your training zones from there. Remember, they’re formulas based on data about the general population — not data based on you.

 

Use the Talk Test

No heart-rate monitor? No watch? Try the talk test: in the recovery zone, you should be able to talk fairly comfortably; in the intermediate zones, talking becomes increasingly difficult as your breathing rate increases, and in the speed and power zone, you should barely be able to grunt out a word between breaths. This simple method requires no gadgets, no counting, and no interruption to your workouts.

Andrew Heffernan CSCS, GCFP

About

Andrew Heffernan, CSCS, GCFP is a fitness coach, Feldenkrais practitioner, and an award-winning health and fitness writer. His work appears regularly in Men's Health and Experience Life. He lives in Los Angeles with his wife and two children. Learn more at andrewheffernan.com

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