Yeah, that's concerning. But there has been research done on how much sleep you need, and at least one study found that 8 hours is too much. I would be ecstatic to get 4 1/2 hours of sleep a night. You get over it pretty quickly. Randonneuring has taught me how to sleep and I'm a lot better at it now.
However, I don't think a 1200k is all that stressful. The most dangerous thing about PBP for the majority of participants is the flight home, because there is a slightly elevated chance of having a stroke. Wear compression socks.
My opinions on this may be colored by my approach, which was to ride a number of 200km brevets before my first series, then a number of super randonneur series before my first 1200k. After having 4 super randonneur series done, nothing about PBP was surprising. Except maybe that it was easier than I thought it would be.
Last edited by unterhausen; 12-14-21 at 08:53 AM.