Is there a polar shift?

Traditionally my greatest times for creative writing has been late at night. Recently that has shifted to early morning (is there a polar shift going on here). I think that I am storing more nervous energy (from various factors) in my physical and I don't fully let it out. I start my morning with various activities that actually release and accept in energy. While this may be okay to some it isn't to me because it means that if I ain't unwinding fully before I go to sleep then I am not getting the full benefits of sleep. Hmmmm...going to have to think on this one.