Yep, I’ve read that and get it. I think my heart rate averaged below 120 bpm on the entire kili climb. Similar heart rates in Ecuador. It absolutely makes sense. I’ve been getting the VO2 max tested to figure out my heart rates for training zones but there is also the side of me that wants to push and see how high I can get it. My guide hates running and agrees it’s a waste of time for trekking./mountaineering but after we did a climb of Holy Cross (a real grind), he said “just keep doing whatever it is you’re doing.”
The analogy I use is running is formula one training. Rucking is diesel training – load up like a big truck and just go slow and steady for a long time without stopping.