Hello Mr. Laureano, the "Gimme some bricks" thread got me thinking of something that I saw at a masterclass last year by a very fine trumpet players, and that I've actually heard more than once. He stated that by keeping everything "forward" and being totally efficient he would be able to play all day without ever getting tired, and he claimed to prove that point one time by playing for 14 hours straight one night then going to play a show that same day. I try to be as efficient as I can every time I pick up the horn, but I can't imagine not being tired after say a concert playing Mahler 1, Bruckner 7, and Pictures, or even 14 hours of playing. What I'm trying to say is, do you feel that the efficiency to the level that you guys play at makes your endurance that "unstoppable", or is it the practice time and playing time spent in getting to that efficiency level? Thanks a lot Mr. Laureano.