Breathing from the diaphragm is essential to a well-functioning core and the foundation on which all core exercises should be built. Your core has four parts:
To execute a core breath, sit up straight, put one hand on your belly and the other on your side, and take a full, deep breath. Inhale to expand your diaphragm, and exhale to engage. Be sure use your diaphragm and avoid a “belly breath”.
Once you have full and proper core breathing, you can begin to engage the pelvic floor and other core exercises.