Do not neglect the art of breathing
After every hard work, and from time to time, accustom yourself to relax in the chair, keep your back straight, and take a deep breath in which your stomach moves, and breathe again repeatedly in this way and take in the largest amount of oxygen, as this enters the air to your brain and heart. If we neglect breathing in this way, our distress will increase. In the Holy Qur’an, it is described that those whose chests become constricted are as if they are ascending to heaven. We know that the more we ascend, the amount of oxygen becomes less, and the chest becomes constricted. For this reason, you become accustomed to taking a deep breath after every exhausting mental or physical work in order to regain the openness of your chest. Your thoughts change and you become happier.
From the book Life Skills by Ibrahim Al-Shamlan
