F45 Training is a gym that merges three separate leading-edge fitness training styles into one 45-minute functional training class. The F stands for Functional training, which is a mix of circuit and HIIT style workouts geared towards everyday movement. 45 is the total amount of time for sweat-dripping, heart-pumping fun. The F45 Athletics and Peak Performance Department is comprised of leading training professionals, athletes, and exercise scientists from around the world all dedicated to the research and development of F45 Training workouts.