Sit-up can easily strengthen your core muscles, back and hip muscles. It defines abdominal muscles. Arms, shoulder, chest gets toned up with this exercise. Anyone with heart disease, low back pain must not practice sit-up.
1. Lie down straight on back.
2. Place both the hands straight above the head and keep them on both sides of the ears.
3. Now keeping both the hands straight sit up and touch the toes with your fingers.
4. Head should touch the knees.
5. Again lie down straight with hands straight above head. Do this as suggested by Yoga Doctor.