This Instagram Star Is the World's Most Influential Fitness Trainer

#BBG. #KaylasArmy. If you don’t know these hashtags already, you’re about to. They make regular appearances in the Instagram world on inspiring body transformation photos. And what do they mean? #BBG stands for Bikini Body Guide ($70), a PDF containing 12 weeks of body-changing workouts created by Kayla Itsines (of #KaylasArmy). The Australian personal trainer with a whopping 3.3 million followers on Instagram says her success (and social media celebrity) is somewhat accidental. “I started my Instagram as a personal way to keep track of all my client transformations and home workout videos in one place,” Itsines tells Well+Good. But what she did was start an army of fitness-loving fans. Keep reading to find out how Itsine became the most influential trainer!