So I'm preparing for drum corps and I am struggling with endurance a little in the ballad and a lot in the closer. I usually practice all the music I have every day which usually takes about an hour and the closer I usually get really tired. It's all pretty loud so that might be it, but I'm not playing full volume at home to save my chops and I still struggle. Any advice? If I have to spend 20 minutes on lip slurs after everything, any recommended lip slurs I should do?