Maximum Heart Rate

A comment I received after the last blog, from John Booker, pointed out the concept and calculation of a “Maximum Heart Rate” is a bit more complicated than I had implied. Looking into the subject a bit further than just accepting the simple (and generally accepted and used?) MHR = 220 – Age, I discovered there are not only one or two alternatives but a plethora! Looking at research papers by Gellish, Fox, Tanaka, Hunt, Robergs and Landwehr, to name but a few, were slightly bewildering. For my age, the MHR results ranged from 130 (the Fox 220—age) to 162! Mama mia! The idea of me achieving 162 bpm is bizarre. My legs would drop off and my heart would jump out of my chest!

Years ago, there was a measure of fitness called the Harvard Fitness Index. It involved stepping up on to a one-foot (?) high bench at thirty steps per minute for 2 minutes. This was followed by measuring the recovery heart rate; number of beats at 1 to 1 ½ minutes after the steps, 2 to 2 ½ minutes after and 3 to 3 ½ minutes after stepping. Complex calculations then followed resulting in the Fitness Index. An index of greater than 96 was excellent, 83 to 86 was good, 68 to 82 average, 54 to 67 low average and less than 54 “poor”. How we possibly did all that I can’t remember and how this was all arrived at was shrouded in mystery!! Whether it was for super-fits or couch potatoes, I can’t remember. I don’t do it now!

The current nuance I discovered is Heart Rate Variability. Apparently, everyone has a variable, if apparently steady, heart rate. What observations are taken and after what level of exercise, I haven’t discovered yet. I wonder if it is worth the bother. Maybe it’s worth searching out on the internet.

So, after all this digging about on the internet, I have concluded that good old (220 – Age) as a maximum is ok for me. Easy to calculate, easy to convert to percent of maximum and recordable on the Garmin. So, an hour on the spin bike, reaching 90 to 100 beats per minute (70 to 80 %, say) is the level I’m training at. On a ride, the usual heart rate range is 90 average and a maximum of 110 – but with plenty of rests on the flat and downhill.

Watch this space.