Punches feel different at different times I train

[ecto55]

I think you might be discovering the effect of your bodies' biorhythms on your physical abilities.

If you really want to crack the code, a detailed training diary including diet and sleep routines might help you find some patterns specific to you.

I for one could train early in the morning (run, bag work ect) but never felt right sparring at that time. Each to their own.