The respiratory system needs nourishment for effective function. Have you ever been in outside space during stress & took a deep breath with your eyes closed? A simple inhalation and exhalation gives relaxation & calmness. Yoga also helps de-stressing. 

Moreover, respiratory problems like a cough and cold can enhance fatigue and make us feel weak. It isvery essential to have something to strengthen the body's immunity. Amla, Ashwagandha, Shilajit & Ginsing contributes to internal healing of the body & rejuvenates it.