Your breath is the link between your inner and outer world. Controlled deep breathing helps your body to transform the air you breathe into the energy you need. This stream of energized air produced by properly executed breath can be channelled where needed on demand. Energy cannot be destroyed, but it can be transformed.
Strive daily to breathe more fully and completely, filling from the belly upward to the collarbones. A simple exercise of counting the seconds of your slow inhale and adding a second or more to that exhale can be very effective.
The next time exertion or anxiety allows your breath to quicken and become shallow, simply think about breathing from a foundation of ease and control.
Remember that we can live for a while without food, we can live for a while without water, but how long can we live without our breath?