Originally Posted by
mr_pedro
There is no reason our hearts can't do 250 or 300 bpm if our brain told it to. As it happens it only beats fast enough to provide oxygen and cooling as needed. As you become fitter it is not unthinkable that your muscles are working harder and require more oxygen and cooling.
I have noticed that when I started cycling seriously at 35yr, 170 bpm felt like I was going to collapse, while now 175 feels intense but doable and I max out at 182.
Also it is not adviced to base HR zones on Max HR, better to use LTHR.
This is a technical point, but: Our brains do not control our heart rate (except indirectly via such things as adrenaline or the vagal response). The heart has its own baroreceptors and its own electrical system that control how hard and how fast it beats. And, for some reason not completely understood it does tend to beat slower and slower as we get older and older. For instance, the resting heart rate for an infant of up to 160bpm (with the average being 120-145) can be as high as the maximum heart for an older person.
But that doesn't change your basic point: The heart can beat as fast as it wants...
My (rhetorical) question is: why does it slow down with age? What changes to make it slow down and the max decrease?
Medical science seems to just shrug and say: "It slows down because you are older"... But that avoids the question rather than answers it -- and neither does it answer why some people (like you) are able to maintain their max heart rates as they age.
.... BTW: Good Job!
