Plank Change to PFT

Article by Human Performance Branch, Feb 8, 2023

For decades, the Marine Corps has used crunches to train and assess core muscle strength and endurance. However, research has shown that crunches with the feet restrained require significant hip flexor activation. This has been linked to an increased risk of injury, including lower back pain due to repetitive lumbar flexion. 

The plank presents numerous advantages as an abdominal exercise. Planks build more overall core strength and stability which improves performance. The plank’s engages more muscles compared to the abdominal crunch and limits pressure on the back and neck, reducing potential for injuries in those regions. With increased core strength and stability, Marines are less likely to experience injury or fatigue during functional tasks like lifting and hiking.

In 2020, the Marine Corps adopted the plank as an alternative to crunches for the annual Physical Fitness Test (PFT) to measure core stability, strength, and endurance while reducing risk of injury.  As of 01 Jan 2023, the plank is mandatory and the crunch is no longer authorized. The time required for the maximum score is 3:45. The time required for the minimum score is 1:10. The plank times and scores are gender neutral and remain the same for all ages.