The Ultimate Guide to Unstoppable Motivation

Nir’s Note: Ali Abdaal is a medical doctor turned entrepreneur, and the world’s most-followed productivity expert, with an audience of over 6 million across social media. His new book, Feel-Good Productivity, explores science-backed strategies that help you do more of what matters to you, in a way that’s enjoyable, meaningful, and sustainable.

The Pacific Crest Trail is not for the faint of heart. Spanning 2,650 miles of mountainous terrain in the western United States, it encompasses the entire longitude of America, from the deserts at the Mexican border to the mountains of north Washington. It’s renowned as one of the most arduous — and sometimes dangerous — hiking trails in America.

Every summer, thousands of intrepid walkers set off on the trail, knowing they won’t arrive at the Canadian border until five months later. For most people, this sounds like a hellish feat of endurance. For University of Missouri professor Kennon Sheldon, it sounded like a perfect opportunity for a psychological experiment.

Sheldon is a titanic figure in a recent wave of research into human motivation. At the turn of the millennium, many people thought that the great questions about motivation had been resolved. Since the 1970s, scientists have been aware of the two types of motivation: intrinsic and extrinsic. Intrinsic motivation is…