Position your forearms on top of the stability ball and walk your feet backwards until your body forms a straight line from your head to your feet. Your body should be supported only by your forearms and toes.
Hold this position for the desired period of time.
Comments and tips
The stability ball adds an extra challenge to the typical front plank because it is an unstable surface. This forces more activation from your core muscles to maintain your balance and the plank position.
All muscles are exercised isometrically in this exercise.
Use a mirror to monitor your form. Do not let your lower back sag or your buttocks rise.