In 1997, a retail entrepreneur in British Columbia named Chip Wilson was having back problems. So, like millions of people around the world, he went to a yoga class. What struck Wilson most in his first session wasn’t the poses; it was the pants. He noticed that his yoga instructor was wearing some slinky dance attire, the sort of second skin that makes a fit person’s butt look terrific. Wilson felt inspired to mass-produce this vision of posterior pulchritude. The next year, he started a yoga design-and-fashion business and opened his first store in Vancouver. It was called Lululemon. As a spiritual practice, yoga has been in existence for more than 2,500 years. But in strictly financial terms, Chip Wilson’s 1997 session may have been the most consequential yoga class in world history. In the past two decades, Lululemon has sparked a global fashion revolution, sometimes called “athleisure” or “activewear,” which has injected prodigious quantities of spandex into modern dress and blurred the lines between yoga-and-spin-class attire and normal street clothes. According to one survey, the share of upper-income teenagers who say that athleisure stores like Lululemon are their favorite apparel brands has grown by a factor of six in the past decade. (Incongruously, athleisure has grown in popularity among teens at the same time that American youth sport participation has declined significantly.) Read more at The Atlantic.