STARTING POSITION:
Sit on a mat and rest your heels on the floor. Your knees should be around 90º. Extend your arms by your sides. Contract your pelvic floor and core while keep your body straight.
MOVEMENT:
Begin to lean back and slightly raise your feet until you maintain balance only supported by your glutes. Hold the position during the required time. Return to the starting position with a smooth movement while you inhale. Make sure your shoulder blades are always retracted.
TIPS: The exercise key is quality over quantity. The trick is to perform the exercise using proper form.