In this episode, I explain the biology of breathing (respiration), how it delivers oxygen and carbon dioxide to the cells and tissues of the body and how is best to breathe—nose versus mouth, fast versus slow, deliberately versus reflexively, etc., depending on your health and performance needs. I discuss the positive benefits of breathing properly for mood, to reduce psychological and physiological stress, to halt sleep apnea, and improve facial aesthetics and immune system function. I also compare what is known about the effects and effectiveness of different breathing techniques, including physiological sighs, box breathing and cyclic hyperventilation, “Wim Hof Method,” Prānāyāma yogic breathing and more. I also describe how to breath to optimize learning, memory and reaction time and I explain breathing at high altitudes, why “overbreathing” is bad, and how to breathe specifically to relieve cramps and hiccups. Breathwork practices are zero-cost and require minimal time yet provide a unique and powerful avenue to improve overall quality of life that is grounded in clear physiology. Anyone interesting in improving their mental and physical health or performance in any endeavor ought to benefit from the information and tools in this episode.