There’s really not alot to it.
The plank is one of the most basic exercises.  You start face down, on your forearms and toes, and hold.  That’s really the extent.  Kind of.
When performing this level 1 plank or any progression of it, it is important to remember a few things. 
First, the exerciser must put a slight flexion (forward bend) in the spine.  This keeps the exercisers abdominal flexed preventing the lower back from hyperextending.
Second, the exerciser must “draw in” the belly button up (think of pulling the belly button up to the spine) to keep the TVA (transversus abdominus) active.  The TVA is the deep abdominal tissue whose primary goal is stabilization of the spine.  Working this muscle is the whole point of the plank.
Adding the plank to a workout routine can make drastic improvements to sports performance (the more stable the spine, the more power you will realize from your arms and legs…reference Sports Training Misconceptions article for more info on this).  It can also make a big aesthetic change by causing a corset effect, acting as a hoop around your midsection pulling in.


The plank is a must for all fitness goals and fitness levels, as progressions are available to tax even the very elite athlete. 
So, although basic looking and fairly boring to do, the benefits of performing a plank as a part of a regular workout routine are huge.
Matt Pirtle
Emerge Fitness Staff