Lewis Pugh knows oceans. He was the first to complete a long distance swim in every ocean of the world, and has pioneered more swims around famous landmarks than any other person in history. He swam across the icy waters of the North Pole to highlight the melting of the Arctic Sea ice, and across a glacial lake on Mount Everest to draw attention to the impact of climate change on the Himalayan glaciers. It was there that he met his first yak.

Trekking behind them up the icy slopes, watching them cross skeletal bridges over dizzying ravines, and listening to them breathe outside his tent each night, Lewis got to think about the things he most admires in a yak. And found that those qualities were not unlike the ones that enabled him to meet his own challenges—and achieve things that people believed to be impossible.

In 21 Yaks and a Speedo, Lewis shares his ability to dream big dreams, build crack teams, and get the job done. You'll be inspired by his devotion to excellence, his loyalty to his crew, and his belief in never giving up.

These are 21 strategies Lewis used to achieve what no one thought was possible. The principles are simple but effective. Stick by them, he says, and you will achieve your own impossible.