LES MILLS GRIT™ Athletic is a 30-minute high-intensity interval training (HIIT) sports conditioning workout, designed to make you perform like an athlete. This workout often uses a step, bodyweight exercises and multi-dimensional sports conditioning training to increase your overall athletic performance: strength, agility, speed and power. LES MILLS GRIT Athletic takes cutting-edge HIIT and combines it with powerful music and inspirational coaches who will be down on the floor with you, motivating you to go harder to get fit, fast.