Brian MacKenzie and Anthony Roberts explain the origins of the maximum heart rate number and why it so often tells us so little.
Ever seen this formula?
220 - age = MHR
It’s the standard formula for determining maximum heart rate, or MHR. Subtracting your age from 220 represents the highest heart rate one can safely achieve through exercise stress. This formula tells us a 15-year-old has a maximum heart rate of 205 and a 25-year-old has a maximum heart rate of 195.
If I started training for 5K races at the age of 15 and continued for 10 years, my MHR would still be 195 when I reached 25 years old, according to this formula. After 10 years of endurance training, it would actually be lower than when I started training at 15. The formula tells me I’d have the same maximum heart rate as an untrained person of equal age after endurance training for an entire decade!
Ever wonder where MHR estimates or heart-rate training came from? Have you ever strapped on an HR monitor to see what your heart is doing? Or maybe you checked your resting pulse? It must be important, right? The mainstream medical industry, as well as the general fitness community, has set up parameters for what is healthy based on your resting HR, or RHR.
Fair? Not in the slightest.