Originally Posted by Eric F

HR varies a LOT from person to person. I’m 55yo. My threshold (max sustainable HR) is 170-175bpm. For me, 130bpm is a VERY easy pace. The top end of my Zone 2 is 150bpm.

Maybe 130bpm is your threshold, but you won’t have any real idea until you start monitoring it and getting familiar with how your body actually works.

As for improving climbing ability, it all comes down to power/weight ratio (watts/Kg is the commonly used unit of measure). Improving this number means…
1. Improve power
2. Decrease weight
3. Both of the above