① The changes of EMG of rectus abdominis during abdominal exercise show certain regularity. Take sit-ups as an example, there is obvious EMG activity at the beginning of exercise. When the upper body leans forward 40-60 degrees, the amplitude and frequency of EMG, the amplitude of average integral diagram and muscle tension are the largest. This angle is the most effective angle to improve abdominal muscle strength.

② From the perspective of developing the strength of rectus abdominis, knee-bending sit-ups are better than straight leg sit-ups.

③ Different abdominal exercises have special effects on the abdominal muscles of rectus abdominis, and systematic sit-ups characterized by far gaze can reduce the excitation threshold of the proximal abdominal muscles of rectus abdominis; Systematic leg lifting exercise characterized by near fixation can reduce the excitation threshold of abdominal muscles at the distal end of rectus abdominis; However, systematic supine right-angle sitting exercises can reduce the excited closing value of proximal and distal abdominal muscles of rectus abdominis.

④ To develop abdominal muscles by lifting legs and abdomen, it is best to lift legs and abdomen in supine position.

Extended data:

Rectus abdominis, located on both sides of the midline of the anterior abdominal wall and embedded in the sheath of rectus abdominis, is a band-shaped abdominal muscle with wide upper part and narrow lower part. The inside of the left and right rectus abdominis is bounded by the abdominal white line and separated by 3-4 transverse tendons (dense connective tissue cords) from top to bottom. Tendon stroke is closely combined with the front wall of rectus abdominis sheath to prevent muscle displacement during contraction. The upper end of this muscle starts from the anterior part of the 5th ~ 7th costal cartilage and the xiphoid process of sternum, and ends at the superior margin of pubic bone (between pubic tubercle and pubic symphysis).

In a fixed state, the contraction of muscles on both sides makes the spine bend forward, and the contraction of one side makes the spine bend sideways. During fixation, both sides contract to make pelvis backward. In addition, this muscle has the functions of maintaining abdominal pressure, assisting breathing, defecation and delivery.

Exercise such as supine leg lifting, sit-ups and right-angle support can develop this muscle strength.

The ventral muscle gradually widens backward, reaching the widest in the middle, running in the sheath of rectus abdominis, and gradually narrows at the back, ending in pubic tubercle and pubic crest, accompanied by anterior pubic tendon.

Abdominal training

The abdomen is in the center of the body, which is particularly obvious. From the point of view of human bodybuilding, a truly bodybuilding abdomen should consist of a slender and powerful waist and abdominal muscles with obvious lines. Therefore, please don't neglect abdominal bodybuilding.

First, lateral bending exercises

Stand straight. Separate your legs, raise your arms horizontally, bend your upper body forward, extend your left hand to your right foot, raise your right arm naturally, don't bend your legs and arms, inhale, and then exhale. Repeat in the opposite direction, 8 times in a row.

Second, leg flexion exercise

Keep your arms flat on the ground in supine position, lift your knees at the same time after your legs are straightened, inhale to make your thighs close to your abdomen, then exhale and slowly recover. Repeat 8 times.

Third, lift your legs and abdomen.

Mainly to exercise the lower abdominal muscles. Lie flat on your upper body, straighten your legs as high as possible, and then slowly put them down. After this action, bend your knees and continue to do the same action. Repeat 8 times.

Fourth, sit in the corner.

The supine position is mainly to exercise the upper and lower abdominal muscles. Keep your legs straight, keep your body balanced, then bend your knees and abdomen, so that your abdominal muscles are extremely flexed. During exercise, your feet should not touch the ground or the bed surface.

Five, "cycling" exercise supine position.

Take turns to bend and stretch your legs, imitating the action of pedaling a bicycle, fast and flexible, and the range of flexion and extension is as large as possible. It lasts for 20~30 seconds.

Six, twisting the waist movement

Hold the handle with one hand or pull a certain weight, do waist twisting and turning exercises in various postures, and exercise the external oblique muscles and waist muscles.

Everyone can choose the above exercises according to their own situation, and gradually increase the amount of exercise each time according to their own physical condition, twice a day.

References:

Rectus abdominis _ Baidu Encyclopedia