Deep breathing means - Adopting a habit of breathing deeply.

From your nostril not from your mouth. That's it !

Normally most people ( i.e. almost 95 % of all of us) who are leading a sedentary life style and working on jobs that requires 'using their heads' all day long, the outcome of a busy, complex and demanding life is somewhat like this:

No energy in the end of the day, mental sluggishness, dilapidated bodies, greater susceptibility to germ and infections, wear-and-tear of the entire body, more work for the heart, irregular blood pressure, tensions in body and nerves etc.

Remember this important fact: