220 - Age Max Heart Rate Formula is Garbage

The most widely used formula to predict maximum heart rate is 220 - Age (in years).  I am 46, so my predicted max heart rate is 220 - 46 = 174.  As it turns out, this is not a bad estimate for me.  However, this is purely due to coincidence as the ability of that formula to predict max heart rate is pretty poor.  Take a look at the graph below.  This is actual data from a study that measured maximum heart rate (as opposed to predicting it) in a large number of subjects.  Focus on the two dots in the red circles.  The bottom red circled dot represents a 24 year old subject with a measured max heart rate of 173 beats per minute.  We'll call him low max heart rate guy.  The top red circled dot represents another 24 year old subject, but this one has a max heart rate of 210!!  We'll call him high max heart rate guy.

The standard 220-age formula would predict a max heart rate of 196 beats per minute for both of these 24 year olds.  So what is the big deal?  If I am using a standard heart rate training zone system like the one below to establish heart rate training zones for these two individuals, and we are using 220-age to determine max heart rate, both of them are going to have problems!  Let's illustrate:

Zone 2 training is 75-80% max heart rate.

High max heart rate guy:  220-age predicts a max heart rate of 196 beats per minute.  If we use that figure and compute 75-80% we get 147-156 beats per minute.  However, his actual max heart rate is 210 beats per minute so his real zone 2 is 157-168 beats per minute.  If we use 220-age, we don't work him nearly hard enough!

Low max  heart rate guy:  Again, 220-age predicts a max heart rate of 196 beats per minute.  If we use that figure and compute 75-80% we get 147-156 beats per minute.  However, his true max heart rate is 173 beats per minute so his real zone 2 is 121-138 beats per minute.  If we use 220-age, we are working him WAY too hard.  In fact, by using 220-age to predict his max and then applying the zones above, we would be training him in zone 4 instead of zone 2!  Imagine if we had him doing all of his long runs at this incorrect heart rate zone!  It would be a disaster for his training program.

So is there a better formula to use?  No, not really.  All of the formulas that have been developed so far are just about as bad as this one.  The only way to really know your maximum heart rate is to test it.  There are several ways to do this.  Some people use a series of hill repeats, with each done progressively faster and the last one done at an all out max pace.  Your heart rate immediately after the last repeat will be your max heart rate.  This works if the hill repeat takes at least 2-3 minutes, even at the fastest pace.  Other approaches would use progressively faster 1/2 mile repeats on the track to max.  You can do this on the treadmill by starting at an easy pace and increasing the speed by 1 MPH every minute until you simply cannot go any longer.  Incidentally, if you use a 1% grade, you can use my VO2 max chart from a previous post to estimate your VO2 max from this test as well.  You may not reach absolute max heart rate with any of these approaches (due to residual training fatigue) but it will be very close, and much better than any formula. 

Reference:  The surprising history of the HRmax = 220-age equation, Journal of Exercise Physiology, volume 5 (2), 2002, Robergs, R., and Landwehr, R.