Hang from a pull-up bar with your arms fully extended and your legs straight. Engage your core and lift your legs up towards your chest, keeping them straight. Once your legs are parallel to the ground, twist your hips to one side, bringing your legs towards that side. Pause for a moment, then return to the starting position. Repeat the movement, but this time twist your hips to the opposite side. Continue alternating sides for the desired number of repetitions.
GIF