Breath: The New Science of a Lost Art by James Nestor is a compelling exploration into the overlooked yet vital practice of breathing. Combining scientific research, historical insights, and personal experimentation, Nestor delves into how modern lifestyles have led many to adopt inefficient breathing habits, particularly mouth breathing, and the profound health implications that ensue.  Nestor’s journey takes him from ancient burial sites to cutting-edge laboratories, uncovering the significance of nasal breathing—a practice that filters, humidifies, and regulates airflow, enhancing oxygen absorption and overall health. He highlights how ancient breathing techniques like Pranayama and Tummo, once sidelined, are now gaining recognition for their health benefits. Through his own experiments, including a 10-day period of exclusive mouth breathing, Nestor experiences firsthand the adverse effects of improper breathing, such as increased snoring, sleep apnea, and elevated blood pressure.    The book emphasizes the importance of controlled, rhythmic breathing, advocating for practices like the “perfect breath”—inhaling and exhaling for 5.5 seconds each—to optimize oxygen uptake and promote relaxation. Nestor’s accessible writing and thorough research make Breath not just informative but transformative, offering readers practical tools to improve their breathing and, by extension, their overall well-being