This is a repost of an article from our archives that Jennifer first wrote in 2008, which was then posted on ICA in 2011. It has become the basis for the heart rate training philosophy of the Indoor Cycling Association.

How many times have you heard from your students that the intensity (based on a heart rate you asked for) is just too easy? How many times have you been faced with comments from students that they “rode at 95% for the entire class,” but you know that that would be impossible?

That max HR chart you are using? You might want to toss it for good.

Indoor cycling instructors are faced with a conundrum. The fitness industry is “stuck” on the concept of using age to determine max heart rate (MHR), yet we know it is an incorrect assumption. Even worse, the bogus formula of 220 – age = max heart rate is ubiquitous; almost every cardio machine and heart rate monitor that asks you for your age is using that formula (or a similar one) to prescribe training zones based on MHR.

You’re no better off than if you closed your eyes and threw a dart at the maximum heart rate chart.

Studies have shown that maximum heart rate does not correlate well with age. We know that it doesn’t decline by one beat on your birthday every year. This formula of 220 – age (or 226 – age for females) was never intended by the original authors to be a universal formula; rather, it was intended to prescribe a safe exercise level for patients in cardiac rehab. It was the line of best fit in a regression analysis of limited data.

But somehow, it has stuck. The formula can be off by as much as 20–30 beats in either direction, which is a huge margin of error. This means it may apply to only 30% of the population. In any other industry, those statistics would be considered far too invalid to base a theory upon, but in fitness, it is the cornerstone of many programs.

In my years of personal training, teaching Spinning, coaching athletes, and performing metabolic tests, I have found that more often than not, the age-predicted maximum heart rate (APMHR) formula underestimates MHR. I myself am an anomaly, with an actual maximum that for most of my life was lower than the APMHR (i.e., my MHR was overestimated), so I will use myself as an example to show that if, in fact, the formula does match your MHR, it may only be by coincidence.

When I was 36, I was racing mountain bikes and due to the intense nature of the sport, I often reached my maximum effort in a race. The highest heart rate I ever attained—one that produced a fleeting blurred vision and a sensation of nausea—was 176. I never liked being at this intensity, which might also explain why I didn’t podium (except once in a race with three people!) and was just a middle-of-the-pack rider.

Using the gender-adapted APMHR of 226 – 36 predicted a max HR for me of 190. You can see that my actual maximum was 14 beats lower; that’s significant. Does my lower maximum heart rate mean I am less fit? No, it has little to nothing to do with fitness. MHR is genetically determined. If I didn’t know better, I might have been disappointed in myself that I could not get closer to my supposed “maximum,” even though it was extremely painful at a heart rate of 176.

If this was one of your riders in your cycling classes, they might feel like a failure if they couldn’t get closer to their alleged maximum.

Ten years later, I was no longer racing mountain bikes (thank God!) but on occasion I still reached a painful HR of 176 when out on my mountain bike. And yes, it hurt every bit as much as before to be at that intensity. You can see that my MHR did not decline by 10 beats in that decade.

At age 46, the formula predicted a MHR of 180. Notice that by coincidence, I was now fairly close to the APMHR charts. A couple of years later, I was exactly as “predicted.”

On the other end of the spectrum, those with actual higher maximum heart rates than the charts predict will find that their prescribed training zones based on APMHR are too easy. It’s no wonder why so many people say they feel like they’re doing nothing when they follow the “aerobic” training zones on the charts.

The fitness industry tends to water down almost everything to a formula applicable to a wide variety of less fit people in search of ease over accuracy. But this generates more confusion instead of helping people.

The question becomes, is maximum heart rate even valid as an anchor for training zones? Does it really even matter? The honest answer is, not really! I have completely dumped using MHR charts for good, and it has been a revelatory experience. In my e-book Keep it Real, I discuss the myth of MHR and provide alternate solutions for providing heart rate training zones to indoor cycling students using estimations of lactate threshold and/or ventilatory threshold.

Why is the fitness industry so stuck on using MHR as the determinant for training zones, when there is enough proof that lactate or ventilatory threshold is a much better anchor for training zones and predictor of performance? Why push yourself that hard in a max test, to the point of almost puking, when there are alternative sub-max methods that are even better?

It’s a bit of a dilemma because one cannot expect the average fitness enthusiast to pay for an LT or VO2 max test. The good news is that there is an easier way for the indoor cycling instructor, via doing field tests with your own students. Teaching instructors and students that zones should be based on one’s LTHR and not MHR is a daunting task. The fitness industry is slowly making the transition and educating fitness providers from personal trainers to indoor cycling instructors. But it takes even longer for instructors to educate their clients and students on how to use it.

It’s time instructors take understanding heart rate training seriously.

If you are an instructor teaching indoor cycling, or coaching any sport, hang up your attachment to maximum heart rate and do whatever it takes to learn about threshold-based heart rate training. I’ve provided several resources below that can help you. Please let us know in the comments if you are currently using MHR and thinking about switching to threshold-based zones, or if you have any questions.

{Edit 2014: Over the past four or five years, there has been a steady rise of indoor bikes with power meters across the globe. Power is the most important determinant of output, yet heart rate is still very relevant. Heart rate is the cost to the body of producing that power, so having reliable, personalized, and accurate heart rate training information in conjunction with power is key. The use of power makes it even more important to ditch MHR-based zones in favor of LTHR zones.}

Additional resources:

Keep it Real (In Your Indoor Cycling Classes), e-book by Jennifer Sage.

Joe Friel, Total Heart Rate Training. This is an excellent book that should be in every instructor’s library.

Gina Kolata was one of the first journalists to write about this bogus formula back in 2001 in the New York Times.

Sally Edwards’ article on the Ten Reasons Why 220 – Age is Just Plain Wrong.

The Surprising History of the “HRmax = 220-Age” Equation, Journal of Exercise Physiology Online, Vol 5, No 2, May 2002.

Join ICA

The best way for indoor cycling instructors to learn more about using appropriate heart rate training zones and educating their riders is to join the Indoor Cycling Association.

ICA provides the education for indoor cycling instructors on how to train your students properly using threshold based heart rate zones. We give you the means to explain it to your students as simply as possible.

In doing so, you and your students will have far more success than ever before in reaching weight loss as well as performance goals—you can only imagine how much your riders will love you! That alone will be worth your membership at ICA.