What muscles are trained in sit ups

Sit ups mainly exercise core muscle groups such as rectus abdominis, external oblique abdominis, and iliopsoas, while also stimulating the deep transverse abdominis muscle.

1. rectus abdominis

rectus abdominis is a longitudinal muscle located on both sides of the midline of the anterior abdominal wall, extending from the sternum to the pubic bone. Sit ups, through spinal flexion movements, can effectively stimulate the upper and middle rectus abdominis muscles, helping to shape abdominal lines. This muscle plays an important role in maintaining trunk stability and completing bending movements, and long-term exercise can enhance muscle endurance.

2. External oblique muscle

The external oblique muscle is located on both sides of the abdomen, with muscle fibers distributed diagonally. When performing a rotational sit up, this muscle participates in exerting force and is responsible for the rotation and lateral flexion of the trunk. Moderate exercise can enhance waist strength, but it is necessary to control the amplitude of movements to avoid excessive twisting and muscle strain.

3. Iliopsoas muscle

The iliopsoas muscle connects the lumbar spine and femur, assisting in hip flexion during the sit up phase. Excessive tension in this muscle may lead to lumbar compensation, and it is recommended to cooperate with stretching training. For sedentary individuals, insufficient iliopsoas muscle strength can affect the quality of movement completion.

4. Transverse abdominis

The transverse abdominis is the deepest abdominal muscle, which wraps around the abdominal cavity like a natural band. During sit ups, tightening the abdomen can activate this muscle and enhance core stability. Strengthening the transverse abdominis muscle has a positive effect on improving posture and preventing back pain. It can be attempted to maintain static contraction at the top of the movement.

5. Collaborative muscle group

When performing sit ups, it is also necessary to exert coordinated force from the rectus femoris and sternocleidomastoid muscles. These muscles, although not the primary target muscle group, can affect the movement pattern. It is recommended to keep the chin slightly retracted during training to avoid neck compensation, while also paying attention to the coordination of breathing rhythm and movements.

When doing sit up training, it is recommended to schedule 3-4 times a week, with 3 groups per time and 15-20 times per group, with a 30 second break between groups. In the initial stage, it is possible to lower the difficulty by bending the knees, while advanced learners can try weight-bearing or inclined training. Aerobic exercise and dietary control are necessary to better visualize the contours of the abdominal muscles and avoid muscle imbalance caused by single training. If there is discomfort in the waist, adjust the movements or switch to alternative movements such as abdominal curling. If necessary, consult a professional fitness coach for guidance.