Re: what is difference between breathing with lung and with your belly?

Hi junyoung.

Chances are, your chest does expand during inhalation also, just not as 
noticeably as your belly.  It has to, or there would be very little room 
for the air.  Your belly expands, though, because you aren't properly 
supporting your breathing with your diaphragm.  When this happens, the top 
of the diaphragm moves down in order to create space for your lungs to 
expand.

This method of breathing pushes your abdominal organs out of the way, and 
they have to go somewhere.  So, everything bellies out front.  This is not 
the proper action of the diaphragm, and, incidentally, is why a lot of 
people who aren't overweight, don't drink, and aren't middle-aged have a 
beer belly or a spreading abdomen.

Check out the site at the bottom for more information on the matter.  It's 
not too late to change your habits.  =)

Thanks,
Justin Miller
 http://www.alexander
works.org.uk/breathing.html