Nauli — abdominal isolation and rotation — is described here in its most refined form. The practitioner first learns to contract the rectus abdominis muscles centrally (madhyadeśe), then to rotate them from left to right.

The “best circular movement” (vṛttam uttamam) suggests a controlled undulation of the abdominal muscles, not merely a crude contraction. This technique massages all the internal organs.

Nauli is considered one of the most advanced and beneficial techniques of Haṭha Yoga, strengthening the core and stimulating the digestive system.