Relaxing diaphragmatic breathing focuses on breathing by engaging the diaphragm. Your diaphragm is basically a series of big round, long broad muscles that sit under your lungs. They’re positioned about halfway between your neck and your pelvis. When they go down (breathing in) they fill your lungs up with air that feeds oxygen into your bloodstream. The diaphragm muscles then go up (breathing out) and it forces that air out. Sometimes people have a tendency to ...