It’s been about 20 years since lululemon first introduced what are now known as “yoga pants.” Although yoga is ancient, today it seems inconceivable that yoga would be practiced without the relevant apparel. Active bottoms and leggings alone are now a $1 billion industry according to NPD Group analyst Marshal Cohen. But lululemon and other makers of yoga-related fashion aren’t limited to yoga, they’ve expanded well beyond that and most of what they now make isn’t used for yoga at all. For tapping into that trend and expanding it, lululemon has a total company value of about $15 billion. I recently caught up with my colleague Kim Karmitz who has been doing work with related companies. She explains that lululemon is not alone in benefiting from growth in the yoga business. “It’s not just the big players like adidas, Under Armour and Nike that have grown with yoga,” Karmitz says. ‘“There’s a plethora of smaller companies that have grown up in the same market. They have spawned a much bigger industry than just yoga pants and that’s what we now call ‘athleisure’.” Read more at Forbes.