Weighted Sit-Up

The Sit-Up is a 'classic' abdominal exercise (see technique). The exercise contains two important elements: rounding the back and raising the upper body.

The rectus abdominis (the basis of the 'six-pack') pulls the sternum toward the pelvis by rounding the back.

The rectus femoris brings the thigh toward the pelvis and the bottom of the spine, and vice versa. It is a so-called hip flexor and, in a standing position, brings the thigh forward from the hip joint. In the lying position of the Sit-Up, this brings the entire upper body toward the legs. The weaker sartorius assists the rectus femoris. Shorter muscles that connect the pelvis to the thigh, the psoas major and iliacus, also play an important role in bending from the hip.

The oblique abdominal muscles at the sides stabilize the core throughout the exercise by limiting lateral tilting and rotation. The transverse abdominis (under the oblique abdominal muscles) pulls the abdominal wall inward and thus acts as a natural weightlifting belt to stabilize the core.

In this variation, you place a weight plate on your chest for additional resistance.

Weighted sit-up execution

Choose a weight plate of the desired weight and lie on your back on the floor.

Place your feet flat on the floor, with your knees pointing straight up.

Cross your forearms with the weight plate held as high as possible on your chest.

Bring your chest toward your pelvis by contracting your abdominal muscles. Focus on curving your spine (rounding your back). Your upper back has now come off the floor.

In one smooth movement, continue raising the rest of your upper body.

Slowly bring your upper body back down and backward.

Extend your back until you almost touch the floor.

Weighted sit-up

Active muscles:

Abdomen:

Rectus abdominis
Obliquus externus abdominis (external oblique)
Obliquus internus abdominis (internal oblique)
Musculus transversus abdominis (transverse abdominis, or 'corset muscle')

Pelvis:

Psoas major
Iliacus

Legs:

Rectus femoris
Sartorius

Sit-up technique

Strong abdominal muscles are essential for a strong core and preventing, among other things, lower-back complaints. In practice, many people mainly perform abdominal exercises for a better-looking abdomen. Often with a tight stomach or six-pack as the ultimate goal. In most cases, you do not need to perform abdominal exercises for a flat stomach or six-pack. These are mainly caused by a low body-fat percentage. You cannot specifically burn fat in the abdominal region, including with abdominal exercises. So, as the old saying goes, you mainly make a six-pack in the kitchen.

With a low body-fat percentage, abdominal exercises can make a visual difference. Thicker muscle bellies in the rectus abdominis then create deeper lines in the abdomen. However, the abdominal muscles are used and therefore trained during many different exercises and daily activities. For most people, a low body-fat percentage is therefore enough for a six-pack. In some exceptional cases, the muscle bellies (the 'blocks') of the rectus abdominis are so flat that they are barely visible, even with a low body-fat percentage. Very superficial tendons between the muscle bellies and a linea alba that separates the muscle bellies can also contribute to this. In those cases, it may be useful to perform abdominal exercises for appearance.

Sit-Ups or Crunches?

As mentioned, you can divide the Sit-Up into two movements. In the second part of the movement, the aforementioned muscles in the legs and pelvis play an important role. Sit-Ups, however, are often performed for stronger or better-looking abdominal muscles. The Sit-Up also places a greater load on the spine while the abdominal muscles themselves work less hard than during a Crunch. A 'classic exercise' in this case therefore partly means 'outdated'. Sit-Ups have declined significantly in popularity in favor of the Crunch, which is essentially only the first part of the Sit-Up.

Moreover, when you place a large weight plate on your body that covers both the chest and abdomen, you make it almost impossible to bring the chest toward the pelvis.

Feet secured or not

With Sit-ups, it can prove difficult to get past the 'sticking point', especially with additional weight. Momentum is often needed to raise the upper body. If you want to perform the movement purely through muscular strength, it can therefore be helpful to secure your feet or have them held in place.

At a glance