Barbell Core Rotation on Bosu -
Start: stand upright on a bosu, holding a barbell behind the neck, and resting across the shoulders.
Action: Keeping the torso upright, and without moving the legs or hips, rotate the torso to the left or right as far as is comfortable.
End: Rotate the torso back to the centre and continue to twist to the other side as far as is comfortable. Continue to rotate the torso from one side to the other for the required number of repetitions.