This test forms part of the Navy Physical Readiness Test (PRT), performed by US Navy personnel every six months. For the navy this test is called the curl up, though others may call it a sit-up or crunch.

• purpose: This test measures the endurance of the abdominal and hip-flexor muscles.
• equipment required: a level surface on a blanket, mat, or other suitable padding, stopwatch
• procedure: The aim of this test is to perform as many sit-ups as you can in two minutes. The starting position is lying on your back with your knees bent (heels approximately 10 inches from your buttocks) and feet flat on the floor. Arms should be folded across your chest with hands touching your upper chest or shoulders. A second person is permitted to hold the lower legs or ankles to keep the feet on the floor. On the command ‘go,’ start the crunch by raising your upper body forward till the elbows touch the thighs while maintaining contact between your hands and chest/shoulders. Then return to the floor until your shoulder blades touch the ground. This is counted as one complete sit up. Repeat this for two minutes.
• scoring: The maximum number of correctly performed sit ups in the allocated time is recorded.
• comments: No bouncing or arching of the lower back is allowed, and the buttocks and feet must remain in constant contact with the floor throughout the test. Resting during the exercise is permitted in either the up position, but cannot hold on to their legs in order to stay up. Shoes are optional.