KS Fitness is a fitness program in Fullerton offering 1-on-1 training, semi-private lifting, glute camp, and boxing/HIIT classes for youth ages 9+ and adults. Its training combines functional movement, boxing, circuit training, weight lifting, natural body weight movement, and high-intensity interval training to challenge people of different fitness levels at their own pace. The gym also offers small class sizes, with kids classes focused on confidence and patience.