Your “diaphragm” is the dome shaped muscle beneath your lungs. When it contracts and flattens, you breathe in. When it relaxes, you breathe out. But do you know your diaphragm plays an important secondary role in protecting your trunk and spine by controlling abdominal pressure?
A well-braced core provides a stable foundation for moving your arms, legs, and head – in much the same way that when firing a canon, a large ship serves as a better platform than a rowboat.
You should not need to always think about proper breathing – this should happen subconsciously. Unfortunately, many of us have “learned” poor mechanics and need to re-learn proper breathing. One of the easiest ways to re-train proper breathing is this exercise: