The bent-over posture we have by the end of a workday does more than give us a sore back — it shuts down our diaphragm. "When the diaphragm is working properly, we breathe in and the muscle contracts, drawing downward to increase the volume of the chest cavity and inflate the lungs," Simanksy says. "When we slouch, there is no place for the diaphragm to move, so the muscles become inactive and weak." This makes our breaths shallow and short, and it also decreases our torso stability. To strengthen this essential muscle, practice diaphragmatic breathing.
Try it: Lie on your back with your knees bent. Place one hand on your upper chest and the other just above your belly button. Breathe in slowly through your nose so that your belly pushes out against your bottom hand, while the hand on your chest remains still. Stop the inhale when the hand on your chest begins to rise. Exhale by tightening your stomach muscles and pulling them inward. Aim for approximately eight breaths per minute for two minutes.