I think you answered your own question as well... I can't imagine I would psychologically be in a good place to run hard after disrupting a sleep cycle and then starting to struggle solo.

Physiologically, I've had the experience of not being able to attain the same heart rates on early morning exercise compared to that later in the day. This is apparently common... an (over 10 years old) article that might have some info worth looking into: https://www.nytimes.com/...utrition/10best.html


This article also mentions most world records are not broken in early-morning competition. Personally I put in most of my training in the morning, but I've almost never tried executing race effort just after rolling out of bed.