USMC Crunches: PFT Rules MCO P6100.12  MARINE CORPS PHYSICAL FITNESS TEST AND BODY COMPOSITION PROGRAM MANUAL Abdominal Crunch. The goal of the abdominal crunch event is for a Marine to execute as many proper and complete crunches within the prescribed time limit. The procedures are: (1) 2-minute time limit. (2) On a flat surface, Marines will lie flat on their back with shoulder blades touching … Continue reading USMC Crunches Video: PFT Rules