LES MILLS CORE™ is a scientific core workout that uses athletic training principles to build strength, stability and endurance in the muscles that support your core. Each workout features a mix of proven core exercises and new integrated core training innovations. The integrated core training moves hone in on the torso and sling muscles that connect your upper body to your lower body. Thanks to these integrated exercises you can simultaneously and effectively work all the large muscle groups from shoulder to the knee, which is one of the fastest ways to improve functional strength and increase athletic performance.