I’m interested in the science and to be honest an opportunity to brag. 46 years of age and quite obviously in my prime.
I have been using TR for about 3 years and my body composition has improved as has my fitness and strength. But interestingly my maximum heart rate has increased by about 4%.
Given that max HR should decrease with age maybe I can milk the stats and say that’s anecdotally more than 4%.
I would be really interested in WHY my heart can cope with a higher max rate. Thank you.
I was under the belief that HRmax cannot be raised through training. Perhaps your previous HRmax measurement was incorrect.
Maybe you have developed a better ability to suffer
Your max HR won’t have increased only your estimation of it as you’ve got fitter. Well done 
Yes. Most assuredly this.
What makes you think you’re at your max now?
Any idea what the margin of error is for your particular HR monitor?
Only way you’re in your “prime” now is if you were on your couch drinking and watching the NFL in your 20’s.
Congrats on all your fitness gains!
Your heart hasn’t learnt to cope with a higher max rate. Your body has learnt how to place a higher demand on your heart while cycling that is pushing it closer to the max that it’s able to cope with.
For context, I’ve always found my max HR when cycling to be lower than other sports I’ve done which recruit more muscles, like rowing and running. When I first started cycling this was quite a big gap, as much as 10bpm. The more cycling I’ve done, the more the gap has narrowed, which I put down to all that cycling training leading to stronger cycling muscles, better bloodflow to them (capillarization), learning how to more effectively use my upper body muscles for stabilisation when doing maximal cycling efforts, etc. All of which adds up to being able to generate a greater overall demand for oxygen when cycling, hence higher max HR.
Increased ability to suffer maybe also a factor if you didn’t have much background in pushing your body to it’s limits before you got into TR and cycling.
This is accurate. I still can’t reach my soccer max HR. H
Interesting and useful answers. I am very grateful. Thanks everyone