There is nothing more essential to our health and wellbeing than breathing: take air in, let it out, repeat 25,000 times a day. Yet, as a species, humans have lost the ability to breathe correctly, with grave consequences.

In Breath, journalist James Nestor travels the world to discover the hidden science behind ancient breathing practices to figure out what went wrong and how to fix it.

Modern research is showing us that making even slight adjustments to the way we inhale and exhale can:

• improve our exercise techniques
• restore healthy sleep patterns and minimise snoring
• halt allergies, asthma and even autoimmune disease

Drawing on thousands of years of ancient wisdom and cutting-edge studies, Breath is full of revelations, turning what we thought we knew about our most basic biological function on its head.

You will never breathe the same again.

From the author of the international Bestseller Breath Covering a diving championship in Greece on a hot and sticky assignment for Outside magazine, James Nestor discovered free diving. He had stumbled on one of the most extreme sports in existence: a quest to extend the frontiers of human experience, in which divers descend without breathing equipment, for hundreds of feet below the water, for minutes after they should have died from lack of oxygen. Sometimes they emerge unconscious, or bleeding from the nose and ears, and sometimes they don't come up at all. The free divers were Nestor's way into an exhilarating and dangerous world of deep-sea pioneers, underwater athletes, scientists, spear fishermen, billionaires and ordinary men and women who are poised on the brink of some amazing discoveries about the ocean. Soon he was visiting the scientists who live 60ft underwater (and are permanently high on nitrous dioxide), swimming with the notorious man-eating sharks of Reunion and descending thousands of feet in a homemade submarine. And on the way down, he learnt about the amazing amphibious reflexes activated in the human body under deep-water conditions, why dolphins were injected with LSD in an attempt to teach them to talk, and why sharks like AC/DC. The sea covers seventy per cent of Earth's surface, and still contains answers to questions about the world we are only beginning to ask: Deep blends science and adventure to uncover its amazing secrets.

From the bestselling author of Breath, a “fascinating, informative, exhilarating” voyage from the ocean’s surface to its darkest trenches (Wall Street Journal).

Fascinated by the sport of freediving—in which competitors descend great depths on a single breath—James Nestor embeds with a gang of oceangoing extreme athletes and renegade researchers. He finds whales that communicate with other whales hundreds of miles away, sharks that swim in unerringly straight lines through pitch-black waters, and other strange phenomena. Most illuminating of all, he learns that these abilities are reflected in our own remarkable, and often hidden, potential—including echolocation, directional sense, and the profound bodily changes humans undergo when underwater.

Along the way, Nestor unlocks his own freediving skills as he communes with the pioneers who are expanding our definition of what is possible in the natural world, and in ourselves.