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The One-Size-Fits-All Age Adjusted Maximum Heart Rate Equation Fits No One

January 01, 2017 — Sally Edwards, MA, MBA, Author, Exercise Scientist, CEO Heart Zones, Inc.©

Position Statement
The 220-minus-age equation regularly used to estimate an individual’s maximum heart rate
(MHR) is invalid for this purpose. The equation, first published in 1970 from data with large
variance, disregards the range of individual differences. MHR in healthy adult individuals
can be as low as 150 beats-per-minute (BPM) and as high as 230 BPM. Because of this
large variance, group data averaged to a mean cannot be used to predict the MHR of individuals
with reasonable accuracy. Such use is inappropriate, inaccurate and can be dangerous
if used to derive exercise prescriptions. There is no equation that accurately estimates
an individual’s MHR or any other human biomarker, including blood pressure or cholesterol
levels. Rather, exercise experts that I work with recommend individual assessments
using a sub-max field test to estimate individual MHRs. We further argue that models
based on population averages usually lead to inaccurate estimates and therefore the MHR
equals 220-minus-age equation should not be used.
Discussion:
By definition, MHR is the highest number of times per minute the heart can contract.
It’s the heart rate at the point of exhaustion in an all-out short effort. An individual maybe
GELLISH, RONALD L.; GOSLIN, BRIAN R.; OLSON, RONALD E.; McDONALD, AUDRY; RUSSI, GARY D.; MOUDGIL, VIRINDER K.
Longitudinal Modeling of the Relationship between Age and Maximal Heart Rate. Medicine & Science in Sports & Exercise.
39(5):822-829, May 2007. “ Although the HRmax-prediction model of 220 - age has become well established in the medical
literature and is used widely in clinical and fitness settings, its validity is uncertain.”
http://www.ncbi.nlm.nih.gov/pubmed/1746858
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be able to continue briefly to increase effort or speed when the actual MHR number is
reached, but the heart simply won’t beat any faster. Most scientists think individual MHR is
a genetically determined number and not based on body size. Rather, MHR is a selfprotecting
mechanism. If the heart beats too fast, it doesn’t have enough time between
beats to fill the chambers adequately in order to fully contract and effectively pump the
volume of blood demanded by the effort.
The 220 BPM minus an individual's age equation for calculating the MHR almost
accidentally became the standard in cardiology and in fitness programs, used in medical,
sports and research. Indeed, an entire industry has grown around the use of this equation,
especially the wearable and exercise equipment-enabled heart rate monitors sold to individuals
and by cardio equipment manufacturers. Though inappropriate, as it is an average
and not an individual number, the MHR 220-minus-age equation continues to be popular
today because it is easy and seems commonsensical. Many exercise gurus, equipment
handbooks, and coaches recite the equation. When learning to use most cardio-exercise
equipment like a treadmill or indoor cycle, often there is a series of questions and one of
this is “How old are you?”. No matter how much science discredits the MHR 220-minus-age
equation, no matter how many research studies invalidate it, too many professionals and
exercise equipment manufacturers continue to believe that one size fits all – that everyone
of the same age has the same MHR. This is false. Every child, every adolescent, and every
adult has her or his own specific MHR, which is unique. That MHR number is genetically not
mathematically determined.
The MHR 220-minus-age equation can lead to potentially dangerous outcomes. Carl
Foster, Ph.D. and the past president of the American College of Sports Medicine, knows
this from personal experience. When Dr. Foster, now professor of Exercise Science at the
University of Wisconsin-La Crosse, was 20 and running collegiate cross country, his coach
demanded that he run near his MHR. The cross country coach used the MHR 220-minusage
equation - Carl’s age, 20, which predicted an MHR of 200 BPM as the goal he should
achieve. But when Dr. Foster tested himself – after all, he was an exercise science major – in
an all out sprint, the highest number that he could ever achieve was160 BPM. He was
humiliated, ridiculed by the running coach in front of his teammates. But in fact, at an all
Batterham, A. M.; George, K. P.; Mullineaux, D. R. RELATIONSHIP BETWEEN HEART SIZE AND BODY DIMENSIONS: AN
ALLOMETRIC SCALING APPROACH: 886. Medicine & Science in Sports & Exercise:
May 1995 - Volume 27 - Issue 5 - ppg S158
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out sprint, Dr. Foster’s genetically determined MHR was within a few heartbeats of 160
BPM. The MHR 220-minus-age equation had a 40 BPM error for Dr. Foster, an egregious
error. Training at too high a heart rate for too long a period, resulting in overtraining, can
lead to hormonal, nutritional, mental, emotional, muscular, neurological and other imbalances.
Physician and consultant to U.S. soccer team, Dr. Donald Kirkendall, Duke University
Medical Center Sports Medicine Section, is another of the professionals who challenge the
seemingly etched-in-stone belief in the 220 minus age equation. In one of his first experiences
analyzing the data from a heart rate monitor was testing a member of the U. S.
rowing team, he told The New York Times. Dr. Kirkendall asked the athlete for an all-out
effort for six minutes. One rower, in his mid-20s, had an estimated maximum heart rate of
195 BPM (220 minutes his age of 25 years or 195 BPM. "His pulse rate hit 200 at 90 seconds
into the test,'' Dr. Kirkendall said. ''And he held it there for the rest of the test'', a
much longer time than would be possible even if his MHR was actually 200, which it wasn’t
– it was substantially higher. A local cardiologist, looking on in astonishment, told Dr. Kirkendall,
''You know, there's not a textbook in the world that says a person could have done
that.’’  The purpose of this White Paper is to support rewriting the textbooks on the 220
minus age equation.
So, why is it important that we know an individual’s MHR? Who created the MHR
220-minus-age equation and made it a belief so strong that even scientific rigor has not yet
corrected it? Why if it is known that the prediction model is inaccurate hasn’t the scientific
community corrected it? And, given the enormous range in MHRs between individuals of
the same age and fitness, why would anyone use the 220 minus age equation today?
Why Do We Need to know Individual MHR?
The 220 minus age MHR prediction is based on group averages of individuals of the
same age. It says that all 10-year olds have the same MHR of 220 minus 10, or an MHR of
210 BPM, and all 50-year olds have the same MHR of 170 BPM or 220 - 50 years. According
to this and most MHR formulas , as you get older, your MHR declines one BPM per year.
Robergs, Robert A. and Landwehr, Roberto. Prediction of Maximal Heart Rate. Journal of Exercise Physiology. Volume 5 Number 2
May 2002.
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This simply is not true.
In medical, research and exercise applications, an accurate measure of MHR is important
as it is used for exercise testing and prescriptions for some of the following reasons:
• Determining the intensity of the exercise during a workout is often expressed as a
percentage of MHR. For example, the average target heart rate for the workout
might be only 72% of maximum effort.
• It is used to assess the fitness level. For example, an individual is becoming fitter
because he or she is achieving a higher percentage of MHR for a longer period of
exercise time.
• It becomes a criterion for achieving maximal exertion: For example, the individual’s
MHR is 180 BPM and in a high intensity interval training session (HIIT) the individual
reached 170 BPM three times.
• For prescribing individual training zones for safe exercise activities in both the
healthy and unhealthy population.
In exercise and fitness applications, MHR is
used in both training and racing. One of the most
important reasons to assess one’s MHR accurately
and individually is to use that number as an anchor to
set training zones. The chart in Figure 1, while based
on an individual’s 220 minus age equation estimated
MHR, can be used once the MHR is determined by
ignoring the age axis. Simply use the MHR for the
individual. Using heart rate training zones allows the
fitness enthusiast a way to easily determine relative,
working heart rate zones or workout zones using a
wearable heart rate monitor. By using a zone training
method, an individual can work out simply using
percentages of the MHR number.
Figures 1. Using MHR To Set Training Zones
Based On MHR Equation 220 Minus Age.
(©FITNUSPOSTERS)
Over the last quarter century, dozens of scientists have tried to demonstrate that there is a
more accurate measure of MHR by adding more than just age as a variable in the equation.
There now are MHR equations based on ethnicity, gender, fitness levels, weight and other
factors. And yet, there simply is no way to mathematically determine something that needs
to be measured individually. Among practitioners who agree is exercise medicine
researcher Mark Sarzynski’s, PhD, Assistant Professor of Exercise Science, University of
South Carolina. “Our findings show that based on the standard error of estimates, the
prevailing age-based, estimated HR max equations do not precisely predict an individual’s
measured MHR.”
How is Maximum Heart Rate Determined?
There are two common ways to measure the individual MHR. The first way is to estimate
MHR in either an all out effort or with sub-max testing protocols. The second but erroneous
way to assess MHR for the individual is to use one of the many formulas from population
averages. Once the MHR is determined, that number in BPM can then be used as an
J Am Coll Cardiol. 2001;37(1):153-156. doi:10.1016/S0735-1097(00)01054-8
M.A. SARZYNSKI,1, T. RANKINEN,1 C.P. EARNEST,2 A.S. LEON,3 D.C. RAO,4 J.S. SKINNER,5 and C. BOUCHARD1.
Measured Maximal Heart Rates Compared to Commonly Used Age-Based Prediction Equations in the Heritage Family
StudyAm J Hum Biol. 2013 Sep-Oct; 25(5): 695–701.
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3935487/
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Figures 2. Heart Zones Calculated On 10% Of Measured Maximum Heart Rate (©Heart Zones, Inc)
a splattergram of dots because the individual differences (i.e., variance) in MHR are so
immense. He and researchers who followed took the average of each age group regardless
of fitness level, plotted it and drew a regression line that showed that MHR drops by 1 BPM
anchor point or value to calculate individual heart rate training zones, which are typically
marked in 10% intervals of the MHR number.
The Maximum Heart Rate chart herein shows five training zones each based on 10
per cent intervals of one's individual MHR. First published in 1993, The Heart Rate Monitor
Book , this chart removes all factors used in the earlier equations such as age or gender.
By anchoring training zones on one’s actual individual MHR and setting goals based on
percentages of a valid MHR number, a person or trainer can more accurately assess the
appropriate amount of time to allot to each zone, arguably providing improved health and
fitness benefits.
Where did the MHR equals 220-minus-age equation originate?
In 1927 Harvard University created the prestigious Harvard Fatigue Lab dedicated to
Heart Zones Inc copyright 1993
Carl Foster, The Bloodless Lactate Profile. Medicine and Science in Sports and Exercise, pp 927-933, 1995.
S. Edwards. The Heart Rate Monitor Book. Polar Electro Oy, 1993.
http://www.humankinetics.com/excerpts/excerpts/harvard-fatigue-laboratory-influential-in-promoting-exercise-physiology-research
Robergs, Robert A. and Landwehr, Roberto. Prediction of Maximal Heart Rate. Journal of Exercise Physiology. Volume 5 Number 2
May 2002.
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Figure 3. Splattergram of red dots are individual MHRs.
The blue line is the regression line for the one-size-fits all
equation. (Roberg)
promoting scientific and collaborative
research in exercise physiology. Then doctoral
candidate Sid Robinson, who later
became a professor at University of Indiana,
published a paper that showed the MHR of
different age groups. This is called crosssectional
versus longitudinal research. Robinson
compared a group of 20-year olds with a
group of 30-year olds and so forth. The
fitness levels were not measured nor were
individuals screened for medication usage or
health issues. Robinson’s results appeared like
Fox SM, III, Naughton JP, Haskell WL. Physical activity and the prevention of coronary heart disease. Ann Clin Res. 1971;3:404–432. [
Robergs RA, Landwehr R. The surprising history of the “HRmax=220 minus age” equation. J Exerc Physiol online. 2002;5:1–10.
Nes BM1, Janszky I, Wisløff U, Støylen A, Karlsen T. Age-predicted maximal heart rate in healthy subjects: The HUNT fitness study.
Scand J Med Sci Sports. 2013 Dec;23(6):697-704. 2012 Feb 29.
http://www.nytimes.com/2001/04/24/health/maximum-heart-rate-theory-is-challenged.html?pagewanted=all
per year. Today, longitudinal research does show that measured MHR may drop by age,
especially in those who become unfit, but the rate of decline of MHR is individualistic, and
that in large part as fitness declines the ability to reach MHR declines. That is the individual
being tested may not have the strength or the stamina to reach their true MHR in a testing
situation. Indeed, this decline in individual MHR may be the result of their individual inability
to reach MHR rather than the MHR actually declining. There is currently no known
research to assess this decline in MHR-testing capacity in the older population.
But, where did the one-size-fits all equation, the MHR 220-minus-age, originate? In
1970, three exercise medicine specialists in the Public Health Service, Fox, Naughton, and
Haskell first derived and published it as a solution to a problem. At the time, Dr. Samuel
Fox was leading a program on heart health and was mentoring Dr. William Haskell.
Together, with researcher J.P. Naughton, they were in search for a way to prescribe safe
exercise intensities for cardiac patients.
But, according to Robert A. Robergs and Roberto Landwehr in the Journal of Exercise
Physiology, “Surprisingly, there is no published record of research for this equation.” It
was not the Fox team's intention to create something that would become the foundation of
aerobic exercise intensity levels, they simply sought a quick way to establish levels of effort
in order to prescribe safe exercise. They were working with sick patients, not kids, fitnessseekers,
or athletes and they needed to provide these patients with safe exercise prescriptions.
Today there are a number of different equations and the argument continues
concerning which is the best equation with the least amount of error. In fact, all such equations
to mathematically calculate MHR are equally useless. ''I've kind of laughed about it
over the years,'' Dr. William Haskell told The New York Times in 2001. The equation, he
said, ''was never supposed to be an absolute guide to rule people's training.'' (For a more
complete story about how the MHR equal 220 minus age equation became "perceived
wisdom" read the entire New York Times article. )
Why Do Some Individuals have a Higher MHR than Others of the Same Age?
Given identical age, fitness level, gender and all other factors, how can non-smokers
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Circulation. 2010 Jul 13;122(2):130-7. doi: 10.1161/CIRCULATIONAHA.110.939249. 2010 Jun 28.
Heart rate response to exercise stress testing in asymptomatic women: the st. James women take heart project.
Gulati M1, Shaw LJ, Thisted RA, Black HR, Bairey Merz CN, Arnsdorf MF.
Dev Med Child Neurol. 2011 Sep;53(9):861-4. doi: 10.1111/j.1469-8749.2011.03989.x. Epub 2011 May 13.Maximum heart rate for
children: The 220-age equation does not predict maximum heart rate in children and adolescents.
http://www.ncbi.nlm.nih.gov/pubmed/21569015
Ten different Sub-Max tests are available in the Heart Rate Monitor Guidebook by Edwards. Heart Zones publishing 2010 available
at www.HeartZones.com
who are disease and medication-free individuals have as high as an 80 BPM difference in
their tested MHRs. A perhaps whimsical answer lies in the differences between the heart
rate of a hummingbird versus that of a blue whale.
First, let’s take the hummingbird’s heart beat frequency - more than 20 times each
second - or as high as 1,260 beats per minute. A hummingbird's heart is tiny, smaller than
the size of an aspirin. Next, compare a hummingbird's heart to the world's largest heart -
that of the seven-ton blue whale. A blue whale's heart can be as big as a room. The cardiac
frequency of hummers and whales varies from individual to individual just like humans, but
in general, larger animals have a slower heat rate than smaller animals. The average heart
rate of large whales is from about 10 BPM to a MHR of 30 BPM.
But, a more technical answer to the question why there is such an enormous range in
MHR between two individuals of the same weight, size, and other factors has to do with
heart mass. The bigger the dimensions, the size and weight of your heart, the lower your
MHR – you are a blue whale. And conversely, the smaller your heart mass is as compared to
your body size, the higher your MHR – you are a hummingbird.
What Can Be Done to change the Practice of Using the MHR Equals 220-Minus-Age Equation?
There is a better way to estimate MHR than erroneously using a one-size fits all equation,
which recent research has shown is especially inappropriate for women and children .
Our recommendation is to estimate an individuals MHR using a safe and time-efficient
sub-max field test. A field test or field experiment is different from a lab test. The field test
is conducted in the same use environment or conditions of normal exercise instead of in a
controlled environment like a laboratory.
There are several different sub-max tests and when done in combination, these field tests
are almost as accurate as an all-out MHR test. See the example of one of the “EasyModerate-Hard
Sub-Max” field tests presented here in Figure 3.
Let's use the Easy-Moderate-Hard Sub Max Test as an example. After an adequate
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Giancarlo Condello,1, Ezekiel Reynolds,2, Carl Foster,2,3,Jos J. de Koning,2,3, Erika Casolino,1, Megan Knutson,2, and John P.
Porcari2, A Simplified Approach for Estimating the Ventilatory and Respiratory Compensation Thresholds J Sports Sci Med. 2014
May; 13(2): 309–314. 2014 May 1.
warm-up, the participant begins the first of three stages of an activity of their choice at an
effort level that matches a feeling of effort best described as “Easy”. After two minutes the
participant records the number of beats-per-minute (BPM) that matches the feeling of Easy.
Using the RPE, Rating of Perceived Exertion scale of 0 being no effort and 10 representing
a feeling of all-out effort, the Easy level of intensity is a rating of 2. The second stage of the
test is to immediately increase the intensity of the same activity to a moderate level that
would be best represented on the RPE between a 4 to a 6 rating effort level. Again, after
two minutes of moderate effort, the participant record their BPM for Moderate. The final
2-minute stage is at a hard to very hard level of intensity equal to a 6-7 on the scale of
perceived exertion. Taking the BPM from all three stages of the Sub-Max Field Test the
resulting estimate of MHR for this participant would be as185 BPM. See Table 1.
Convert from MHR to Threshold Heart Rate
There is another way to anchor individual training zones which is not based on maximum
heart rate. This method is called the threshold heart rate method. Many exercise
scientists and researchers today recommend this method of assessing for threshold heart
rates because as your fitness level changes so does your threshold heart rate numbers.
Threshold heart rate numbers are dynamic while the MHR number does not change with
fitness.
Threshold biomarkers are measured when there is a shift in the energy requirements,
the carbohydrates and fats, that are burned during an exercise session. The most accurate
way to assess the threshold biomarkers is in an exercise laboratory while field tests for the
threshold heart rate have been scientifically validated. There are two different threshold
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Table 1. Calculating MHR from the Easy-Moderate-Hard Sub-Max Field Test
Current Effort Level: Easy Moderate Hard
120 BPM 145 BPM 170 BPM
MHR: 185 BPM
+60
180 BPM
+40
185 BPM
+20
190 BPM
Add the Math Factor:
Estimated MHR from Field Test:
exercise intensities called the first threshold (T1) or the low threshold. The second threshold
(T2) or the high threshold is commonly called the ventilatory or lactate threshold and
formerly known as the anaerobic threshold. By doing a field test for T1 and T2, dynamic
heart rate zones can be set as shown in Figure 5. Threshold Training System.
Ibid M.A. SARZYNSKI
Conclusion
The MHR 220-minus-age equation – still in use in health clubs, schools, medical settings,
and among many coaches today – has been proven to be outdated and inaccurate.
Mark Sarzynski, PhD, a prolific researcher in personalized exercise medicine at the Arnold
School of Public Health at the University of South Carolina’s concluded, “Our results fail to
validate the effectiveness of either of the two most widely used age-based HRmax prediction
equations in sedentary, healthy adults. These results suggest that it may be very diffi-
cult, perhaps even impossible, to predict with a low standard estimate of error HRmax from
age.
That certainly has been the conclusion – and experience – of Carl Foster, the former
collegiate cross country runner with the mere 160 BPM MHR who now is Professor of Exercise
Science at the University of Wisconsin, La Crosse as well as the past editor of the International
Journal of Sports Physiology and Performance. "There is not one equation that is
meaningful or any better than any other equation," he wrote, "except for some very specific
uses in medical practice, I think that the use of any predicted MHR should not be used
in the exercise industry, in schools, and for other uses because it is useless at best, and
dangerous at worst.”
Using equations that predict MHR individually is a fruitless process because individuals
simply have too much variance in MHR. Rather, an individual's MHR should be estimated
using sub-max field tests with results used to derive training zones specific to the
individual as well as help in the development of safe and appropriate exercise prescriptions
for individuals.
There is no reason to continue using the 45-year old MHR 220-minus-age equation
given what we know today.
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Sally Edwards, MA, MBA, Physical Educator, is the CEO and founder of Heart Zones, Inc,
the fitness technology company for Smart health and fitness. She is the author of 25 books
on exercise, triathlon and running, and weight loss. She currently develops heart rate technology
and programs for schools, health clubs, corporate wellness, sports teams, and rehabilitation
centers.
Ms.Edwards has been an avid heart rate monitor user since she qualified and competed
in the 1984 Olympic Trials guided by her Polar© heart rate monitor 32-years ago.
Her oft-stated goal in life is to get America fit and one way is to use wearables like a heart
rate monitor. She developed the Blink line of heart rate monitors and sensors for her program,
Heart Zones Training™. A professional runner and triathlete, she first established the
first five zone MHR system in 1992 in her first book on using a wearable for health and
fitness The Heart Rate Monitor Book. She continues today to debunk the myth that MHR
can be determined by any mathematical equation.
She can be reached at (1) 916.481.7283 or by email sally.edwards@heartzones.com .
She lives and works in Sacramento, California.

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