One of the best ways to naturally strengthen your lungs is to breathe properly. Inhale from your diaphragm, expanding and pushing out the muscles in your lower belly. As you exhale, your muscles should retract back inward. Inhale and then exhale. As you do both, count the seconds it takes to breathe. Try to gradually extend the time it takes to breathe by one or two counts. Be sure not to strain yourself or hold your breath for too long. This could cause you to deprive oxygen to the brain, which could cause dizziness, or fainting Sitting and standing up straight can help you breathe so your lungs gain strength. An exercise to help expand the capacity of your lung, is to sit on a chair with your back straight, and lift your arms above your head while breathing deeply.

How would you rephrase that briefly using Chinese?
学会高效呼吸。 数数。 改善身体姿势。