Sit-up

Sit-up is a calisthenics exercise designed to strengthen the abdominal muscles. It is similar to a crunch, but sit-ups have a fuller range of motion and condition additional muscles.

Procedure

A sit-up is performed by lying down on the back on the floor, typically with the arms across the chest or hands behind the head and the knees bent in an attempt to reduce stress on the back muscles and spine, and then elevating both the upper and lower vertebrae from the floor until everything superior to the buttocks is not touching the ground. Some argue that situps can be dangerous due to high compressive lumbar load and may be replaced with the crunch in an exercise program.

Muscles involved

The sit-up targets the rectus abdominis muscle, which flexes the spine. This muscle compresses the abdomen, so you would use this muscle when you cough or if you were to blow out a candle. The sit-up also targets the hip flexors, which bring the torso towards the legs.

Variations

There are many variations of the sit-up. The most common is the vertical sit up where the exerciser makes a movement of the body in a vertical direction by keeping the legs stationary and using the hips to lift the back off the ground. Other variations include the use of a stability ball or a decline bench.

See also

• Crunch (exercise)
• Push-up
• Squat (exercise)

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  Sit-up
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  Seabees conducting sit-ups during the Navy Physical Readiness Test