I am a brand new member. Actually, I just registered half an hour ago. I have got a problem which is very much linked to my practice, though it may seems strange that call it a problem. When I started really practicing towards achieving a decent lip trill, my lips were getting tired, so I tried to depend more on my breathing. As a result my lips seems to get less pressure as the lip stamina increased, but my diaphragm now seems to get tired and sometimes I feel a little pain there. Do you know of any exercises of building that kind of stamina, or the reaction is just normal?