The anti-rotation Russian twist is a trunk stability exercise that improves the ability to resist influence by rotational forces. It’s simply a Russian twist in which only the weight moves while the trunk remains approximately motionless. It’s best done with the feet anchored, such as in a GHD, decline sit-up board, or with the toes fixed under a machine or dumbbells, but can be done seated on the floor as well.
 
In a partial sit-up position, hold a plate, medicine ball or other weighted implement in the hands and move it from one side to the other without allowing the trunk to rotate with it. The straighter the arms, the heavier the weight, and the faster the motion, the more difficult it will be. 
 
Notes
The shoulders will rotate someone unavoidably—focus on keeping the sternum facing forward to minimize rotation of the trunk as a whole.
 
Purpose
The anti-rotation Russian twist develops strength and stability to maintain trunk position in the presence of rotational forces. It’s also an isometric trunk flexion and hip flexor exercise. It’s a good addition to the more common exercises that address anti-flexion, anti-rotation, and anti-lateral flexion to establish more complete trunk stability and control.
 
Programming
The anti-rotation Russian twist should generally be done at the end of training sessions. Sets of 8-15 reps in each direction are recommended.
 
Variations
The anti-rotation Russian twist can be done with any weighted implement—plate, dumbbell, kettlebell, medicine ball, sandbag, etc. It can also be done on the floor or in a GHD or decline sit-up board, but ideally in any case the feet are anchored to allow a more solid position and greater reach with the arms. Speed can be anywhere from very slow to very fast—slower speed will force longer time under tension, while faster speed will demand resistance against greater force to stop the weight at the end of the range of motion on each side.