Ah...the reason I asked is because I had low BP when I was younger (it’s still lower than average but more healthy/normal as I get older), couldn’t give blood during blood drives, and was always sluggish waking up in the AM.
Well, though, I must admit that I am more of a night person than a morning person. In the morning, I may have faster reaction times, but in the evening, I can think much clearer.