How do you do a Plank?
Begin on your hands and knees, with hands shoulder-width apart and knees hip-width apart.
Straighten your legs out behind you and rise onto the balls of your feet. Keep your arms straight, but not locked, with your shoulders aligned over your hands. Your body should be in a straight diagonal line from your shoulders to your toes.
How do you modify a Plank?
Plank for Beginners
Plank for Weak Wrists
What are the benefits of a Plank?
Once you build up the strength to hold for 60 seconds, try adding a leg lift.
While holding your plank, lift your right leg one inch off of the ground. Hold for 30 seconds and switch sides. This will help to not only challenge your core, but also improve your balance and focus.
Michele Gordon,Power Studios in New York City