The HSD, like 4C, trains the hip and upper thigh areas three-dimensionally, developing the basic strength and mobility needed for stability to perform functional movements. In reconditioning, the HSD is performed daily immediately after 4C and before engaging in other PRT activities. During the toughening phase, the HSD is performed after preparation and prior to endurance and mobility activities. The HSD may also be performed outside regular PRT sessions as supplemental training. In the HSD, perform no more than 10 repetitions of exercises 1 through 4 and do not exceed 30 seconds for each exercise position in exercise 5. If more repetitions are desired, repeat the entire drill.