[Supine Crunch] mainly exercises abdominal muscles. Lie on your back on a mat, place your hands on either side of your head, bend your knees, and place your feet hip-width apart. Inhale first, then slowly roll up the torso until the upper back leaves the mat, making sure that the waist does not leave the mat. Exhale at the same time, pause for a moment, and then slowly return to the ready position, but the head does not touch the mat; inhale at the same time. Common mistakes: Holding your head with both hands when standing up can easily cause neck injury. Do 3 sets x 20 times.
