After trying the local "Hill" I was surprised to see my heart rate dropped substantially despite subjectively putting in a lot of effort. How can I maintain constant cardiovascular effort to all the way to the top of the hill?
I'm a moderately fit, mid-forties man. I'm in my local running club, I parkrun 5k in 23min etc. I ride to work daily (about 4miles along a disused railway path). While I'm furloughed, I've been trying to maintain fitness on my bike by doing some longer rides and up the local Hill, nicknamed "The Wall" on Ashdown forest, Sussex, about 1.5km with a gradient between 8 and 10. I monitor my HR with a Polar 200 watch.
And I've found it pretty tough!
That wasn't a big surprise, but I was surprised to see that my heart rate dropped substantially during the climb from about 140 to about 90-95 on the second (steeper) section of the climb. A HR of 95 would normally be "brisk walk" level of effort. But subjectively it felt "very hard" with burning legs and heavy breathing. I found it necessary to drop right down to the lowest gear to keep going.
Is this drop in HR expected? What should I be doing to ensure that I am able to push consistently all the way to the top?
My ultimate goal would be "build CV health", but my medium-term motivational goal is "get up The Wall as quickly as possible."
The research I've done such as https://www.cyclingweekly.com/fitness/training/improve-your-climbing-353501 mostly focusses on "how to lower your heart rate while climbing".