Itsines

Itsines refers to Kayla Itsines, an Australian fitness trainer and entrepreneur whose work has shaped modern digital fitness. Emerging from social media in the early 2010s, Itsines built a large following by sharing workout guidance, progress photos, and nutrition tips on Instagram. In 2014 she co-founded the Bikini Body Guides (BBG), a 12-week program of mostly bodyweight workouts intended for home use. The program was published as a series of ebooks and online guides and contributed to a wave of internet-based fitness coaching aimed at women.

Itsines and her business partner, Tobi Pearce, expanded the brand beyond the BBG program by launching the Sweat app in 2016. Sweat offers guided video workouts, nutrition plans, and community features and has grown to include programs from multiple trainers and fitness categories, reaching a global audience.

In addition to its digital programs, the Itsines brand has released printed guides, apparel collaborations, and other media ventures. Itsines' influence in fitness media and online coaching is widely recognized, and Itsines has been cited as a leading figure in the movement toward at-home workouts and influencer-led fitness brands. The business model centers on scalable digital products, recurring subscriptions, and social media marketing. Critics have noted that marketing and diet-focused messaging characteristic of many fitness programs may not suit everyone, underscoring the ongoing debates around fitness industry claims and commercialization.