Russian twist is a common abdominal muscle training movement, which can exercise rectus abdominis, internal oblique muscle and external oblique muscle. Here are some key points of Russian twist:

1. Lie on the yoga mat, with legs and feet crossed, knees slightly bent, and make an imaginary V-shape between trunk and thigh.

2. Arms are fully extended in front of you and perpendicular to your body, hands are clenched, waist and abdomen are contracted at the same time, and the right side is twisted.

3. Keep the contraction of the second action back to the starting position, exhale at the same time, and then move to the other side to do the same action on the right side.