Travis Macy summited glacial peaks in the French Alps, rappelled into vast limestone caves in China, and ran through parched deserts in Utah. Most famously, he won one of the country's marquee ultra-distance events: Leadman, a high-altitude series of super-long-distance races, culminating with a 100-mile mountain biking race and a 100-mile trail run. Macy accomplished it without exceptional strength, speed, or flexibility, and without high-tech performance labs or performance-enhancing drugs.

His secret? A precise and particular outlook he calls the "Ultra Mindset," principles for daily...