Generally when you ride a steady state Zone 2 ride for example there may come a point where you heart rate gradually starts to increase the longer you go. The fitter you are the longer or harder you may be able to ride before that happens. This I found out is called heart rate decoupling, where you heart rate starts to “decouple” from the expected heart rate for a known effort. I have a different issue which is called Negative heart rate decoupling where my heart rate actually reduces the longer I ride at a steady effort. This is apparently a good thing and shows that all the long Zone 2 type efforts (which I have been doing much more of lately) is working? I need to do well over a hour but by the time I hit 2 hours plus my HR drops about 10 bpm for the same effort and I actually feel better (apart from a bit of leg ache) towards the end of the ride than the beginning?? My Zone 2 HR range is only 24 bpm so a 10 bpm drop is huge. Anyone else experience this?
Only 24 bpm? And that’s a range?
That’s a number that’s not typical.
It is at my age of 70. Max HR is 149… Z1- 0 to 94…Z2- 95 to 117… Z3- 118 to 129…Z4- 130-136 ( LTHR)…Z5- 137+ etc So actually, its 22 and not 24 beats!
That may be a question for a coach.
As an older cyclist myself I have a couple thoughts;
One possibility is that it just takes you longer to get warmed up so your true power/hr ratio doesn’t show up accurately till aftrr the first hour. I know it takes me at least 30 minutes to feel good and an hour is even better (especially if I did a hard ride the previous day).
Another may be that you are experiencing fatigue in the heart muscle itself that causes your hr to drop over time at the same effort. I have experienced this phenomenon on longer, more intense rides/races (over 50 miles) where my hr drifts lower toward the end because it just can’t sustain the effort anymore. Haven’t experienced that on a Z2 ride though…
Thanks for your observations. The thing is, I actually feel better and if I do push it more I can get my HR to go back up again albeit at more power than I would expect for that HR.
IDK about my HR, but I’m also ‘older’ and find I feel better and stronger an hour or more into a ride. Many of my rides are fairly strenuous 2-3 hr mtb rides and the last half feels better than the first.
Thanks. I read your post incorrectly. While the range is a good value I cannot add anything that others have stated. I’m 64 and like others have said, it takes my old self a long time to get warmed up however I do not see a drop of HR versus power like you seem to see.
Same age and I saw this a couple of times. I didn’t think about it as this was after a recovery day.
I view it as a sign of excellent endurance. Keep it up! 