Group Functional Training Classes. HIIT Nutritional Challenges Cardio, Resistance and MMA/ Boxing Classes F45 Training Hawthorn is a Functional Training Gym, that gives members access to seven classes per day. The group training classes are High Intensity Workouts that combines both strength, and aerobic conditioning, the F45 style is a holistic approach to training, combining only the best parts of all cardio and resistance techniques. A group training experience that can only be described as unique, innovative, dynamic and most importantly FUN! F45 is a cult; it has to be experienced to believe. So much so, the brand has now trained Ricky Martin, Joel Madden, and Nicole Richie to name a few.