Hang the rings at a medium height and make a supine grip with your hands near your hips. Bring your upper-body forward so that you reach a 45-degree angle to the ground with your arms stretched. From that position bend your elbows to return to the initial position. Adjust the height of the rings to change the difficulty: the lower, harder.
legs, core, obliques
legs, buttocks, calves, femoral, quadriceps