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

abdominal muscles Abdominal muscles cover the anterior and lateral abdominal region and meet at the anterior midline. These muscles of the anterolateral abdominal wall can be divided into four groups: the external obliques, the internal obliques, the transversus abd ...

. It is similar to a curl-up (that targets the

rectus abdominis The rectus abdominis muscle, () also known as the "abdominal muscle" or simply better known as the "abs", is a pair of segmented skeletal muscle on the ventral aspect of a person, person's abdomen. The paired muscle is separated at the midline b ...

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

Form

Sit-ups begin with the practicing individual lying with their back on the floor. Typically, this is done with the arms across the chest or hands behind the head. The knees and toes are bent to reduce stress on the back muscles and spine. Both the upper and lower

vertebrae Each vertebra (: vertebrae) is an irregular bone with a complex structure composed of bone and some hyaline cartilage, that make up the vertebral column or spine, of vertebrates. The proportions of the vertebrae differ according to their spinal ...

are elevated from the floor until everything superior to the

buttocks The buttocks (: 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 of a lay ...

is not touching the ground. Some argue that sit-ups 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 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 increa ...

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 have been found to 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, Spinal disc herniation, herniated discs, and Vertebral compression fracture, fractured verteb ...

. In 2015, it was revealed that every branch of the U.S. armed forces have begun to phase out sit-ups and crunches, due to the high rates of lower-back injury. They have been replaced by planks.

References

{{Strength training exercises Bodyweight exercises Aerobic exercise

Form

Variations

Health risks

See also

References