# Finding my physiologically relevant maximum heart rate

I've always believed my maximum heart rate was 198 based on my performance. I'm 24 years old, so 220-24 = 196, but I routinely hit 197/198 during hard efforts in many rides, and never exceeded 198. When I hit 198 I can barely sustain my level of exertion and have to ease off in short order.

Then one day I blew that number out the window when I sustained 202 for almost 20 seconds on a huge sprint effort. After the effort I had to get off the bike since I was dizzy and could hardly hold my head up and grasp the bars.

So, for the purpose of defining my heart rate zones, is my "max" 202 or 198?

• 220-age is just a guestimate and you can basically ignore it. Commented Sep 6, 2019 at 16:56
• A 1% difference is rightly insignificant. Even a 10% difference is. The other thing is that HR measuring devices aren't that precise. Commented Sep 6, 2019 at 18:00
• 2% (4 in 200) is within the measurement error anyway Commented Sep 6, 2019 at 18:48
• So, for the purpose of defining my heart rate zones, is my "max" 202 or 198? It's 202 until you exceed 202 when something happens, such as you start actual racing and get a death wobble on a fast descent during a race, and while trying to control it start drifting over the yellow lines into oncoming traffic. Then you set a new max heart rate... In other words, max HR is useless. Commented Sep 10, 2019 at 9:43

The 220 - age (or any age based formula) is a myth that works well enough for roughly 60% of the population and puts the other 40% wrong. That it persists to this day with such ready access to HR monitors and reasonably accurate sub-maximal tests to determine max HR astounds me. (I blew over 210 when I was in my early 30's and now over 50 can sustain 170 for a hour and can probably reach 190.)

Training zones based on max heart rate percentages are based on average people and well enough for most of the population, but they are guesstimates. You do not gain more accuracy from knowing max HR to a few beat per minute.

Presuming your HR monitor is accurate, your maximum is clearly at least 202. For defining your training zones, use 200 - its a nice round number.

• Definitely this. When I was in my 30s I could regularly hit 210+ doing anaerobic intervals. I can still hit 200; at threshold (race pace) I'm around 180-185. Commented Sep 7, 2019 at 1:19
• 210 actual measurement vs. 190 estimate is “only” a 10% error. I also wonder how accurate your 210bpm examples are. My Garmin strap suddenly jumps to 240 when I go above 200. Commented Sep 9, 2019 at 11:51
• works well enough for roughly 60% of the population I'd be surprised if it were that accurate.given the standard deviation for max HR is something like 10 or 12 bpm. There's a decent difference between 170 and 180 bpm, enough that if you try basing your threshold HR off of your `220 - age` HR and are off by 10 bpm, you won't be working at threshold when you think you are. If your actual LTHR is 160 bpm, riding at 170 bpm will be way too hard, and riding at 150 bpm way too easy for the intended level of effort. Commented Sep 10, 2019 at 9:46
• Thanks for the answer, but I have to suspect there is variability in HRM accuracy between models and even within use of a unit. My HRM has been incredibly consistent, and I can't imagine how I could physiologically handle anything higher than 202 on a bike. Maybe some people are built different, I ride with some folks my age who easily spend 10 minutes above 200 bpm on a 1-2hr group ride--crazy. I'd rather not pick an arbitrary number though, and I like the idea of basing HR zones on LTHR very much. That's a reproducible non-arbitrary metric. Commented Sep 10, 2019 at 13:05
• @Anderew - My "The Population" includes those that bought a Fitbit for walking the dog and want a number telling them they are 'doing good'.These people have no idea what Lactic acid is, let along that it has threshold :) Commented Sep 10, 2019 at 20:11

Max HR isn't a particularly useful metric.
Not only is it particularly difficult to measure/estimate, but it can't be used to accurately define training zones, as there are large variations between individuals with regards to % of MHR they can sustain for various durations. It can even change for an individual based on their current state of training.

Basing zones on Lactate Threshold Heart Rate (LTHR) is a much more useful metric for determining appropriate training zones. The most common way to determine LTHR is by performing a 30 minute solo time trial as if it were a race, and taking the average HR for the last 20 minutes of the effort. https://www.trainingpeaks.com/blog/joe-friel-s-quick-guide-to-setting-zones/

• Any pointers on where/how to do this? Commented Sep 9, 2019 at 10:50
• Yes, sure. There's a few different protocols with some minor differences, but i'll update the post with the most common one. Commented Sep 9, 2019 at 11:05
• Thanks! Interesting; that's close enough to the protocol for an FTP test I could probably do that as well next time I test FTP... I only knew of the ramp test, and that's problematic. Commented Sep 9, 2019 at 11:25
• I really like the idea of basing HR zones on LTHR. Thanks for the bringing up idea and link! It seems more scientific and reproducible. Commented Sep 10, 2019 at 13:02

Whatever maximum you have achieved on a bike is your maximum verified heart rate. Since you have reached 202, it is at least 202. Ignore the formulas since you already know better.

If you have an indoor trainer, or you have access to an exercise bike with a power meter, I would perform what is called a ramp test: Start with very easy pedaling for ten minutes or so, to get warmed up. Then, start increasing power by 30 watts every 2 minutes, and continue until you simply cannot turn the pedals any longer. Your heart rate is guaranteed to sky rocket, and whatever you reach should be considered your maximum heart rate in cycling.

This test protocol is used when determiming lactate threshold and maximum oxygen intake in athletes. Personally, at the end of ramp tests I have had my heart rate ticking steady at exactly 200 for the last couple of minutes -- It is the physiological maximum for me. I have only reached 190 a few times outdoors, and at the end of long intervals (at threshold) it is commonly about 175.

• So yeah I do have a power meter and have done ramp tests, only get up to 198 :) And I'm no chicken, I've taken a lot of Strava KOMs at 194-198 bpm. Thanks! Commented Sep 10, 2019 at 12:55