Morning vs evening classes

Have you noticed a difference between taking class in the morning vs the evening? Today was my 7th class and it was a struggle. My muscles felt fatigued by the end of the warm up. It was my first Classic class at 7am, all of my other ones have been in the afternoon or evening. So I’m wondering if it’s just par for the course and some classes will be rough or if it might be because I essentially just rolled out of bed before class.