TThe TR applies the train for combat proficiency concept to PRT. Running through local training areas, over hills, and around obstacles improves mobility, endurance, and the ability to stop, start, and change direction. Terrain running is designed to be conducted with small unit integrity. This type of running is best performed by squads and sections. Distances should generally be 1 mile for densely wooded areas and up to 2 miles on tank trails and open fields. Intensity is relative to the terrain. Physical readiness training leaders will form the unit and maintain an interval suitable for the terrain and environmental conditions. Soldiers should perform terrain running in ACUs and well-fitting boots. Soldiers may progress to performing terrain running with IBA, ACH, individual weapon, and under fighting load. Refer to Table 10-2 for endurance and mobility activities, prescriptions of intensity, duration, and volume within the toughening and sustaining phases. In addition, Chapter 5, Planning Considerations, provides the template for commanders and PRT leaders to implement endurance and mobility activities into their PRT programs.