There are a few articles and scientific studies on the topic, e.g.
https://www.row2k.com/features/5903/tim ... u-can-use/
For another one the abstract can be read, but the full article comes at a price (or by courtesy of the authors)
https://pubmed.ncbi.nlm.nih.gov/18978619/
I could download free of charge one article that considers brain blood flow differences between morning and afternoon (measured with a probe on the head, hence 'cerebrovascular' in the title)
https://onlinelibrary.wiley.com/doi/abs ... /sms.12273
Article on the general morning/afternoon/evening effect in sports performance :
https://vitruve.fit/blog/time-in-training-performance/