Sit-Up

Sets of 3 repetitions 10

Lie down on the floor with your knees bent, with the balls of your feet and heels on the ground.
Place your hands behind the earlobes, or even hold your ears.
Tighten your abdominal muscles by drawing in your navel to your spine.
Keeping your heels on the ground, slowly lift your head and shoulder blades off the floor with a contraction of the abdominal muscles. Lift your shoulder blades off the floor as high as you are comfortable with.
Hold the position for a second, then slowly bring the torso back to the floor, trying to keep it slightly off the ground (i.e., try not to "lie" on the floor).
Repeat as desired.