It's about how one measures intensity, just like some folks go on about how one measures efficiency. Certainly squatting 3X bodyweight once is pretty intense. Remember all those studies that show greatest VO2 efficiency at about 55 rpm? But yet no one rides like that? Most LD riders that I ride with, meaning folks that regularly do 300k and up, ride a good 100 cadence. It spares glycogen at the expense of slightly increased HR intensity for the power. But it varies with the rider, I don't know why. Lemond rode about 80, Merckx I think was around 115 when he broke the hour record. I've ridden with one LD racer who turns closer to 60 and rides a 90" fixie in the mountains. But most folks take longer to bonk if they spin fast, and do so even if they give up a little power to ride at that HR intensity when riding LD for time. Sort of like 250 mile TTing.