Hello,
I noticed a better performance in the morning, both with heavy lifts and cardio. Excepted some singles in the evening, I've always trained in the morning, while I am fresh and never had any issue.
For a while, I tried to train in the evening, with bad results (lack of stamina, bad posture...)
I think what hurts CNS is working until failure or even "almost failure" on a daily basis.
Kind regards,
Pet'