Originally Posted by MonsieurChrono

Speed is one thing, but, even though I am relatively young, I'm not that fast myself so agreeing with this wouldn't say much; however, with regard to endurance, there are some pensioners in a nearby city called Assas for instance that do 100 to 200 km rides on a weekly basis.

They organize and they themselves take part in some brevets between 200 and 1 000 km, and some of these are particulary ridiculous, like the following one that is 200 km long and involves 5+ km of climbing: https://www.openrunner.com/route-details/10495044

To arrive at the steep sections (sustained > 10%) of the Col de la Lusette 190 km into the ride with more than 4 km of climbing already is a bit insane, it's not in my foreseeable plans btw, perhaps after 10 years of cycling under my belt.