The Marine Corps will be removing crunches from its physical fitness test in favor of planks by 2023, according to a Navy administrative notice released Thursday.
“The isometric hold of the plank requires constant muscle activation, uses almost twice as many muscles as the crunch, and reliably measures the endurance of the midsection required for military duties and everyday activities,” wrote Lieutenant General Lewis Craparotta, commanding general of the Corps ‘Training and Education Command, in the notice of changes.
Sometimes referred to as a front hold, a plank is a core isometric exercise that involves maintaining a push-up-like position with body weight on the forearms or hands.
In response to feedback from the Marines, the Corps added the plank to its physical fitness test in 2020 as an alternative to crunches, with a minimum hold time of 1 minute, three seconds to pass, and a hold time of 4 minutes, 20 seconds considered the perfect result. But as of January 1, 2022, the corps will adjust these requirements slightly, increasing the minimum to 1 minute 10 seconds and lowering the maximum to 3 minutes 45 seconds, the news said. The plank will become the new standard in 2023.
“From January 1, 2023, the plank will be mandatory for the PFT and the stomach crunch will no longer be an alternative to the plank,” says the message. “This MARADMIN serves as an advance notice to ensure that the Marines have sufficient time to prepare and prepare for the plank event prior to the policy change in CY 2023.”
The Marine Corps’ updated ordinance on physical fitness and combat fitness tests is slated to be released before the end of 2021, according to a Marine spokesman.
As an instructional video from Marine Corps Base Quantico explains, planks must be made on a level surface and the Marines begin in a push-up position with feet hip-width apart and toes extended. Once they put their weight on their forearms and hands, “the back, buttocks, and legs must be straight from head to heels,” explains one Marine narrator, “and must remain so throughout the test.”
U.S. Marine Corps 1st Lt. Philip Sartain (left), a field artillery officer, with Battery C, 1st Battalion, 11th Marine Regiment, 1st Marine Division and Warrant Officer Tanner L. Grace (right), a weapons repair officer, with 1st Battalion, 11th Marine Regiment, 1st Marine Division, perform an exercise during high-intensity interval training at Marine Corps Base Camp Pendleton, Calif., March 12, 2021. Chris Hinshaw, an elite athletic trainer, conducted training sessions and health lectures with attendees to enable them to adequately coach their assigned Marines to achieve optimal combat fitness. (U.S. Marine Corps Photo by Lance Cpl. Quince Bisard)
Individual physical training representatives will monitor no more than seven Marines while they conduct the exercise and will call 15-second intervals to complete, according to Major Lindsey Slyman of the Marine Corps Human Performance Branch. The time is called when a Marine falls to the ground, raises his feet or hands, or does not hold a straight line with his body, although verbal warning is allowed.
“For decades, the Marine Corps has used crunches to improve and assess abdominal endurance,” said Captain Sam Stephenson, a Navy spokesman. “However, research has shown that restrained foot crunches require significant hip flexor activation. This has been linked to an increased risk of injury, including lower back pain from increased lumbar lordosis. “
“Marines experience less injury or fatigue when performing functional tasks like walking, lifting, and low crawling,” added Stephenson.
In fact, a research paper sent to the Navy Commander in 2018 found that lower back pain was the “leading” musculoskeletal diagnosis treated at clinics in Camp Lejeune, North Carolina, such as this, between 2017 and 2018 Marine Corps Times reported. The crunch was “ineffective in assessing functional core strength” and “arguably harmful to back health,” says the paper. In contrast, the plank exercise was found to “relieve the pressure on the lower back” and received good marks from sailors who took part in a study on the 2012 Navy fitness test.
Brian McGuire, a retired Marine Colonel who now heads the Marine Corps’ Human Performance Division, believes the change to the plank will help make the Marines healthier and stronger.
“After years of performing crunches, we now know that crunches with restrained feet require a lot of hip flexor activation and this is associated with an increased risk of injury, particularly lower back pain from repeated lumbar flexion,” McGuire told Task & Purpose. “The isometric hold of the plank requires constant muscle activation, uses almost twice as many muscles as the crunch and reliably measures the endurance of the middle section, which is required for military tasks.”