A growing trend in high-stress, demanding jobs is the “positive stress movement,” when people expose themselves to extreme temperatures, diets and exercise as a way to improve longevity. At Palo Alto Investors, though, the focus is on a far less radical approach to helping us perform better for longer. Dr. Joon Yun is a physician and the president and managing partner of Palo Alto Investors, LLC . He also created and sponsored the Palo Alto Longevity Prize , launched in 2014, which provides a $1