Max Heart rate: Why you shouldn’t use the 220-age formula

Max Heart rate: Why you shouldn’t use the 220-age formula

Article Difficulty: Moderate

Summary:

  • Although it is widely accepted that HRmax decreases with age, research has demonstrated that the 220-age formula is not a valid predictor of HRmax. The formula underpredicts HRmax in older individuals and over-predicts HRmax in younger individuals.
  • A more valid age-formula may be HRmax = 208 − 0.7 × age, this is based on data from a meta analysis of 18,712 people.
  • The best way to calculate HRmax for healthy and physically fit individuals is by using an accurate HR monitor (such as a Polar monitor) and pushing yourself to the limit in a full body cardio based activity such as running.


Before we jump into why you shouldn't use the 220-age formula and look at better options for finding out your maximum heart rate (HRmax), let's first define what HRmax is. HRmax is simply the total number of beats per minute that your heart can achieve. Getting to HRmax requires some serious and intense effort and therefore, it is not generally a recommended training zone. However, as endurance athletes, it is common for us to base heart rate training zones from percentages of HRmax, and many training programs use HRmax percentages for prescribing training intensities and paces. Therefore, having an accurate HRmax is very useful if you’re looking to get the most out of your training.


The most widely used means of calculating HRmax is the 220-age formula, which is widely utilized by athletes, trainers, clinicians, and coaches alike. If you Google ‘how to calculate max heart rate’ you will see the entire first page of results recommending the 220-age calculation. I have come across the formula many times in course texts while studying sport-science. However, it wasn’t until I bought a Polar HR monitor to dig deeper into my heart rate training data that I realized my HRmax is significantly lower than the 220-age calculation. To give some context, I am 28 years old and therefore the calculation suggests my HRmax is 192 (220 bpm - 28), however during my absolute hardest sessions (anywhere between 1-2 miles as fast as possible), I achieve a HRmax of 185 bpm (7 beats below the calculation). Despite my best efforts, I have been unable to surpass this number, and therefore this is most likely my true HRmax. The discrepancy between the age formula and my actual HRmax made me question the validity of the formula, and to explore if my low value is an anomaly or if this common formula is in fact flawed.

I was able to find two well conducted studies on HRmax and age-based formulas. The first took 134 participants and calculated their maximum HR using the 220-age formula and then subjected each participant to a graded treadmill test to identify their true HRmax. They then compared the actual HRmax data with the formula predictions and found a wide range of deviation. As such, they concluded that the formula was generally a poor predictor of actual HRmax (1). The second study took a meta-analytic approach to collect average HRmax values from 351 studies involving 18,712 subjects. They found that in general the 220-age formula under predicted HR max in older individuals and over predicted HRmax in younger individuals (also supported by this study (2) The research they evaluated showed an actual HRmax age decline of 3-5% per decade, whereas the 220 − age equation implies a decline of 5-7% per decade. Instead of the 220-age formula, they presented an updated formula that they found to be of better fit based on the large range of data they analyzed: HR max = 208 − (0.7 × age) . Plugging my numbers into this formula, my HRmax is predicted at 188.4 bpm rather than 192 bpm (220-age formula), and is closer to my actual attained HRmax (185 bpm).

What is the most accurate way of measuring max HR?
For those that are fit and healthy, the most accurate means of gathering true HRmax data is by using an accurate heart rate monitoring device (such as a Polar HR monitor). An effective way to reach HRmax is to undergo high intensity exercise such as running, cycling or rowing for 5-8 minutes with the final 1.5-2 minutes at absolute maximum intensity See this video for a detailed explanation. Various cardio based exercises may be used, however some may find reaching HRmax easier by running or rowing as it recruits more total musculature and therefore more oxygen and thus more cardiac demand.

What determines HRmax and does it change with exercise?
Although the updated calculation is closer to my actual HRmax, it is still lower. This made me question whether HRmax is a fixed value or if it is trainable. There is firm agreement within research that your HRmax is mostly determined by one's genetics. And it is a common belief that the value is fixed and not trainable. In fact, you will see the answer that HRmax does not change with training given across the internet, however I was unable to find any empirical evidence of this. Furthermore, you will find two conflicting findings on coaching sites and forums, one view that HRmax can increase with training and the other that HRmax can decrease with training.

There is limited research on the topic, however I was able to find two studies. The first being a research review which found that HRmax changed in periods of training, tapering and detraining. HRmax decreased during periods of high training and fitness, and HRmax increased when the athletes underwent periods of detraining. The analysis revealed that HRmax may be altered by 3 to 7% between aerobic training and detraining, providing evidence that HRmax can change depending on the state of endurance conditioning (3).

The second study took 130 endurance trained, 40 resistance trained athletes, and 95 age matched sedentary counterparts. They found that both the endurance and resistance trained athletes had significantly lower HRmax than the sedentary individuals by an average of 5 beats per minute. Providing further support that training may indeed lower HRmax (4).

Both studies concluded that the mechanisms behind these changes remain unclear and that until more research is conducted, we should remain cautious about taking the findings as fact. However, what we may be able to glean from this is that age related formulas are likely inadequate beyond a rough prediction as they in no way account for fitness level, which may alter HRmax by 3-7%.



A fitting quote to summarize
‘’The estimation of maximal heart rate (HRmax) has been a feature of exercise physiology and related applied sciences since the late 1930's. The estimation of HRmax has been largely based on the formula; HRmax=220-age. This equation is often presented in textbooks without explanation or citation to original research. In addition, the formula and related concepts are included in most certification exams within sports medicine, exercise physiology, and fitness. Despite the acceptance of this formula, research spanning more than two decades reveals the large error inherent in the estimation of HRmax. Ironically, inquiry into the history of this formula reveals that it was not developed from original research, but resulted from observation based on data from approximately 11 references consisting of published research or unpublished scientific compilations. Consequently, the formula HRmax=220 -age has no scientific merit for use in exercise physiology and related fields.’’ (5)

References:

  1. Shookster, D., Lindsey, B., Cortes, N., & Martin, J. R. (2020). Accuracy of Commonly Used Age-Predicted Maximal Heart Rate Equations. International journal of exercise science, 13(7), 1242–1250. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7523886/
  2. Cruz-Martínez, Luis Eduardo, Rojas-Valencia, Jaime Tomás, Correa-Mesa, Juan Felipe, & Correa-Morales, Carlos. (2014). Maximum Heart Rate during exercise: Reliability of the 220-age and Tanaka formulas in healthy young people at a moderate elevation. Revista de la Facultad de Medicina, 62(4), 579-585. Retrieved August 12, 2023, http://www.scielo.org.co/scielo.php?script=sci_arttext&pid=S0120-00112014000400010#:~:text=Other%20studies%20confirm%20that%20the,19%2C%2027%2D32).
  3. Zavorsky G. S. (2000). Evidence and possible mechanisms of altered maximum heart rate with endurance training and tapering. Sports medicine (Auckland, N.Z.), 29(1), 13–26. https://doi.org/10.2165/00007256-200029010-00002
  4. Whyte, G. P., George, K., Shave, R., Middleton, N., & Nevill, A. M. (2008). Training induced changes in maximum heart rate. International journal of sports medicine, 29(2), 129–133. https://doi.org/10.1055/s-2007-965783
  5. Robergs, Robert & Landwehr, Roberto. (2002). The surprising history of the "HRmax=220-age" equation. International Journal of Online Engineering - iJOE. 5. https://www.researchgate.net/publication/237258265_The_surprising_history_of_the_HRmax220-age_equation
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