"Abdominal contraction" is the action of trunk flexion, with a small range of activities, only the abdominal muscles participate. The traditional "sit-ups" take the hip joint as the axis to exercise, and the hip joint and trunk are flexed at the same time, with a wide range of activities, and the iliopsoas, rectus femoris and abdominal muscles all participate in the exercise. The difference between the two is that the hip joint does not move; Sit-ups have an active effect on the hip joint. Due to the activity of the hip joint, the distance between the "iliopsoas muscle" connected by thoracic vertebra 12 and lumbar vertebra 1-5 and the thigh and femur will be shortened after strengthening, which will lead to the incorrect posture of lumbar forward bending and pelvis forward for a long time, which will increase back pressure and lead to low back pain.

The correct way to roll your stomach is:

Lie flat on the mat, legs bent, legs at about 90 degrees, feet flat on the ground, abdomen closed, chin slightly closed. Cross your hands on your chest or ears, and be careful not to use force. Start the action: slowly lift the scapula and middle back away from the mat, keep the lumbar spine from leaving the mat, control for one or two seconds, slowly recover the scapula to avoid touching the mat or slightly, and then repeat the action. It's like a sit-up in the middle. If you want to enhance the exercise effect, you can follow the principles of lengthening the arm, increasing the torque and improving the training intensity. For example, move your hand from your chest to your ear; Or raise your arms above your head; Or holding a small dumbbell in both hands; You can also leave your feet off the ground, with your calves parallel to the ground and your thighs about 90 degrees.

? Teach you five main points of supine belly roll:

1. Do you feel nervous in your neck? When you bend forward, do the muscles on both sides of your ears protrude? If so, try another way. Support your head with a towel. If you feel neck fatigue, stop exercising immediately.

2. Do you feel pressure on your lower back? If so, it proves that the abdominal muscles are not fully active. When you begin to exhale, the first breath of 1/4 should be used to help you call your navel toward the ground-when you feel your abdominal muscles fully active, then start to bend forward. If you have a herniated disc, make sure your feet are off the ground when doing this exercise.

3. Do you lean forward slightly? Enough: Pilates abdominal flexion is a small exercise, and the key point is to exercise the muscles correctly. When you become strong, you can bend a little more. Don't compare with the so-called athletes you see in the gym. It is true that they naturally hit their knees with their heads, but it is also because of this strength that varicose veins are caused.

If you find that your abdomen bulges or your muscles are lumpy, it means that you are bent too much. When bending forward, the height of the helper should not be higher than the crotch. In the whole process, I think that the chest is becoming flexible.

5. Do you feel pressure on the inner thigh? If there is, it means that you are clamping the mat tightly between your thighs. Try another method, with your feet off the ground:

When you are sure that your movements are correct, then start to exercise your abdominal muscles and repeat 10 times.