"Here's a nauli. With your head down, rotate the inside of your abdomen to the right and left in a slow motion, like a whirlpool in a river. This is called nauli.
Nauli Kriya eliminates indolence of the stomach, enhances digestion, gives a feeling of pleasure and destroys all ailments. This is the most important of all the kriyas (purifications) of Hatha Yoga. "Hatha Yoga Pradipika" (2.33 - 34)
Nauli is the practice of contracting and isolating the rectus abdominis muscles.
When the rectus abdominis muscles rotate from left to right (counterclockwise), this is called dakshina - nauli.
When they rotate from right to left (clockwise), it is vama - nauli.
When the muscles are pulled together and the middle muscle group protrudes, it is Madhyama-nauli. Before attempting nauli, one must master uddiyana bandha and agnisara kriya.
To master the nauli technique perfectly, it is necessary to make the abdominal muscles mobile and elastic. First, it is recommended to master the technique of rotating the abdominal muscles clockwise and counterclockwise in different planes of the body. This will strengthen the abdominal walls and prepare you to master the practice of nauli.
Restriction: Those suffering from heart disease, stomach ulcers and duodenal ulcers should not practice nauli. This also applies to those who have undergone abdominal surgery in the past year.
First, you practice nauli with your body tilted forward and your hands resting on your hips just above your knees. The higher the hands are placed on the hips, the more complex the form of nauli is practiced.
Nauli option 1
Stage 1
Spread your feet shoulder-width apart. Bend your knees and support your hands just above the knees; the thumbs on the inner thighs and the rest of the fingers on the outer thighs. The head is straight, the eyes are open.
Inhale deeply through your nose and exhale quickly through your mouth.
Perform jalandhara bandha and uddiyana bandha while holding the breath.
Raise your right arm slightly above the knee, keeping your weight on your left arm and knee, but do not bend over to the left. This will automatically isolate the rectus abdominis muscles on the left side.
Then release uddiyana bandha and jalandhara bandha, stand up straight and inhale slowly. This is vama-nauli.
Practice in the same way on the right side. Keep your right hand over your knee and slightly raise your left hand to isolate the rectus abdominis muscles on the right side. This is dakshina-nauli.
Between every two nauli cycles, first release uddiyana bandha, then jalandhara bandha, raise your head, stand up straight, and then inhale very slowly through your nose.
Take a few normal breaths in and out before performing the next cycle.
Stage 2
Practice vama-nauli or dakshina-nauli as in the first option, and then start rolling the muscles to the other side, but before they reach the opposite side, hold them in the middle.
In order to move the muscles to the other side, lightly transfer your weight to the hand that was previously removed from the knee.
When the muscles are in the center, both hands should remain above the knees. This is madhyama nauli.
Stage 3
Practice in the same way as in the first and second stages, but now without raising your hands from the knees, only relaxing the pressure of the hand on the leg, but without removing it from the leg. Gradually, the hands on the hips should remain motionless. Then do this practice by placing your hands on your upper thighs.
Option 2
Repeat the previous option, rotating the muscles clockwise (vama-nauli). This action is called "shaking". Start by doing three cycles in succession, then rest a little.
Perform dakshina-nauli in the same way, rotating the muscles counterclockwise.
When this agitation is perfect, practice vama-nauli three times, then dakshina-nauli three times, and then relaxation.
When you are perfect in this, you can do ten rotations, then twenty rotations.
Option 3
Practice options 1 and 2 while sitting in Padmasana, Siddhasana, or Siddha Yoni Asana, lifting your buttocks slightly with a pillow.
Initially, it will be difficult to control the muscles while sitting, so you must first achieve excellence in this practice while standing.