Sit down in chair, close eyes and concentrate on breathing slow and deep, "Go' breathing or Dan Tien,, Hira Geza or what ever name and language you learned. GO is 5 in Japanese, a 5 and 10 count breathing with inhale full breath at 5, then slow exhale to 10 but at 5 you tighten butt and stomach 6/Royku is calves and thighs, sichi is back muscles, Haichi/8 is pectoral muscle, Ku/9 is arm and wrist, Ju/10 is neck. You'll have really emptied lungs then, relax body and slow breath in at start of next count. . Breath in through nose, out through mouth, empty lungs on 10 and refill to 5/Go before out breath and muscle tightening, diaphram tightening with stomach movement to next 10. repeat 5 time to start, concentrate on the timing, breathing and muscle tightening in set order. Mind will clear, lungs will clear some, Lymphatic system will get blood back to heart and increase oxygen in blood will get to brain. Yoga practicioners have similar breathing and tightening drills, some on 4 count, QuiGong is Chinese term for the breathing , Tai Chi drill has soft movements and breathing.