I used to be of the philosophy that I would practice no matter how beat my chops were. This practice only encouraged bad habits and really hurt my playing. I did this for so many years - how foolish. Now when I feel tired, I put the horn away and take the day off. I am not doing any professional performing right now so I can do this. When I go through a very gentle warmup in the morning I can tell how much the day before has taken out of my face. I am in much better shape after a day off and can resume my normal routine and continue to play correctly. By the way, a carefully planned warmup , to me, is the best way to approach the trumpet. How do other players feel about this?