Plank tight, drag the dumbbell across, no hip sway.
Keep your hips dead level, the win is not rotating while you drag.
Dragging a dumbbell from one side of your body to the other while holding a high plank creates a moving offset load, and your core's job is to keep the hips level while a hand leaves the floor and the weight shifts underneath you. The pull itself is easy, the not-twisting is the work. It is a favourite for teaching rock-solid bracing under changing load.
Light to moderate, it slides along the floor rather than being lifted. If your hips swing to get it moving, go lighter, the drag should never disturb the plank.
Widen your feet for a bigger base, brace before the hand lifts, and drag the dumbbell slowly. Speed and a narrow stance are what let the twist sneak in.
Anything you can drag works, a kettlebell or plate does the same job. The tool matters far less than keeping your hips dead level while it moves.
