The sit-up (or curl-up) is an abdominal endurance training exercise to strengthen, tighten and tone the

abdominal muscles The abdomen (colloquially called the belly, tummy, midriff, tucky or stomach) is the part of the body between the thorax (chest) and pelvis, in humans and in other vertebrates. The abdomen is the front part of the abdominal segment of the torso. ...

. It is similar to a crunch (crunches target the

rectus abdominis The rectus abdominis muscle, ( la, straight abdominal) also known as the "abdominal muscle" or simply the "abs", is a paired straight muscle. It is a paired muscle, separated by a midline band of connective tissue called the linea alba. It exte ...

and also work the

external External may refer to: * External (mathematics), a concept in abstract algebra * Externality In economics, an externality or external cost is an indirect cost or benefit to an uninvolved third party that arises as an effect of another party' ...

and internal obliques), but sit-ups have a fuller range of motion and condition additional muscles.

Form

It begins with lying with the back on the floor, typically with the arms across the chest or hands behind the head and the knees and toes bent in an attempt to reduce stress on the back muscles and spine, and then elevating both the upper and lower

vertebrae The spinal column, a defining synapomorphy shared by nearly all vertebrates, Hagfish are believed to have secondarily lost their spinal column is a moderately flexible series of vertebrae (singular vertebra), each constituting a characteristi ...

from the floor until everything superior to the

buttocks The buttocks (singular: buttock) are two rounded portions of the exterior anatomy of most mammals, located on the posterior of the pelvic region. In humans, the buttocks are located between the lower back and the perineum. They are composed ...

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 exercise programs. Performing alternative abdominal exercises to sit-ups actually increases the ability to do sit-ups. Performing sit-ups do not cause the

spot reduction Spot reduction refers to the claim that fat in a certain area of the body can be targeted for reduction through exercise of specific muscles in that desired area. For example, exercising the abdominal muscles in an effort to lose weight in or aro ...

of fat at the waist. Gaining a " six pack" requires both abdominal

muscle hypertrophy Muscle hypertrophy or muscle building involves a hypertrophy or increase in size of skeletal muscle through a growth in size of its component cells. Two factors contribute to hypertrophy: sarcoplasmic hypertrophy, which focuses more on increas ...

training and fat loss over the abdomen—which can only be done by losing fat from the body as a whole.

Variations

The movement can be made easier by placing the arms further down away from the head. Typical variations to this include crossing the arms to place the palms on the front of the shoulders and extending the arms down to the sides with palms on the floor. The 'arms on shoulders' variation is also used to make the incline sit-up easier. More intense movement is achieved by doing weighted sit-ups, incline sit-ups with arms behind neck and even harder by doing the weighted incline sit-up.

Health risks

With improper form, full sit-ups may cause back pain and arching of the lower back, increasing the risk of

back injury Back injuries result from damage, wear, or trauma to the bones, muscles, or other tissues of the back. Common back injuries include sprains and strains, herniated discs, and fractured vertebrae. The lumbar spine is often the site of back pain. ...

. Since the 2010s, every branch of the U.S. armed forces have begun to phase out sit-ups, due to the high rates of lower-back injury.

References

{{Strength training exercises Bodyweight exercises Aerobic exercise

Form

Variations

Health risks

See also

References