Q I know three ways of calculating maximum heart rate (MHR): 220 – age; 214 – (0.8 x age); and 205 – 1/2 age. For a 30-year-old, they all come out at 190, but for a 60-year-old, the results are 160, 166 and 174 – a large range. Which is the most accurate?
A In general terms, at the start of your 20s, the MHR is about 200 beats per minute (BPM). From then on, the heart gradually slows down, by approximately one beat per year. In endurance athletes, the MHR also slows as a response to prolonged training. Essentially, as it is trained the heart becomes more efficient and therefore slower. Added to this is the natural variation of all of us – the “normal distribution” – of height, weight, blood pressure, MHR and so on. The majority of us are in the middle as “average”, but many lie on either side. Thus some people have a naturally lower MHR and others have a higher one. Formulae can’t legislate for that.
By far the best way to calculate your own rate is to exert yourself as hard as you can, say in a 10-minute hard run, on a reasonably warm day, with a 400m sprint finish, and count your pulse rate for 20 seconds from the very instant you stop running. Multiply that by three, and to whatever value that gives you I would add five BPM, and that can be taken as your “best estimate” of MHR. If you repeat it, and it differs, take the higher value.
Of the various accepted formulae you mention, the one that seems to accord best with “genuine” MHR is 220 – age, but even this is unreliable; it’s best to find out on your own by testing your actual heart rate.
—Professor Craig Sharp, exercise physiologist, Brunel University