[musictlk] running out of breath when singing

[Kelsey Nicolay]

Hello,
During choir rehearsal, I sometimes run out of breath and have to 
breathe discretely in the middle of a phrase.  I do my best to 
use diaphragmatic breathing, but I still run out of breath.  Even 
when laying down, I still find that I tend to use chest 
breathing.  My stomach does expand a little, but not like a good 
breath.  Is this a muscle issue? What can I do to improve my 
breathing?
Thank you,
Kelsey Nicolay