Kneel down facing the landmine with your knees hip-width apart and your back straight. Grasp the landmine barbell with both hands, interlacing your fingers and holding it above and slightly in front of your body.
Keeping your core engaged and your back straight, twist your torso to one side, rotating your arms and the landmine along with it. Pause briefly at the end of the twist, feeling the contraction in your oblique muscles.
Slowly rotate back to the starting position, then twist to the opposite side, repeating the same motion.
Repeat both sides of the rotation for the desired number of reps.
