Kayla Itsines

Kayla Itsines grew up in Adelaide, Australia, in a health-conscious family with Greek parents. Her passion for fitness began early through sports like basketball, which inspired her to study at the Australian Institute of Fitness at age 18, qualifying as a Master Personal Trainer. Initially pursuing beauty therapy and teaching, she pivoted to training at a women-only gym, where she identified women's needs for practical, confidence-building workouts and meal plans. She expanded to group sessions and home bootcamps, posting client transformations on Instagram on her cousin's suggestion, rapidly gaining thousands of followers and global requests for advice. In 2013, Itsines partnered with then-boyfriend Tobi Pearce to launch the Bikini Body Training Company, creating the downloadable Bikini Body Guides (BBG). The guides exploded in popularity, achieving over one million downloads by 2014. The company rebranded to Sweat in 2015, launching the Sweat app, which offered personalized routines and hit the top of app charts. In late 2023, after selling to a U.S. firm, Itsines and Pearce repurchased Sweat, with Itsines reclaiming a leadership role.