Originally Posted by
davester
It's an extremely poor guideline for older people since it was based on a 1930s ad hoc straight line fit of data from young people that was not statistically determined and has subsequently been shown to be a poor fit of even that data. Not only was the methodology poor, but it is completely irrelevant for people over the age of about 30.
Here's a reference that describes the history of the formula:
https://www.researchgate.net/publica...0-age_equation
I had little trouble hitting 200+ at 24 years old. I didn't ride with a monitor (few existed in 1977 but I saw very close to 200 after I stopped and counted with my watch - often at the top of hard hills. Now that formula says my max is 153. I can probably sustain 153 going uphill. (Haven't ridden with a monitor for a while but last year I had to remind myself to back off when I was hitting mid 160s.
My theory? Hearts are (and are like) pumps. Some are big and pump a lot each beat. Some are small and have to pump faster to supply the same amount. If your body was equipped from birth with a big MTB floor pump, it would adopt to a much slower cadence than the body equipped with a mini-pump. No formula based on just on age isn't going to handle both of those pumps.