The other day a friend pulled me aside to ask about heart rate training. He is in his mid 30’s and is mostly an ultra distance runner. “When I was running yesterday, I got my heart rate up to 201, is that possible? Should I use that number to figure out what heart rate zone I should be running in?”
He was confused because of the familiar maximum heart rate formula, “220-age=max HR.” This formula is ubiquitous in the fitness world and lay press, and is used to calculate the HR zones for training at different intensities. This training method is unreliable for a variety of reasons.