Hi Susan! Everyone has done so well giving you their input

I'll go into a little more detail for you.
Planks have become more popular now that core strength and functional fitness are "hot topics" in the fitness world. Research shows us that training for function promotes a better quality of life. It improves posture and conditions the body to perform daily activities more efficiently. Plus, it improves balance, coordination, strength, endurance, and joint integrity. This happens mainly because the selected exercises cause the muscles of the entire body to work together to stabilize the body while also performing against gravity.
Your core muscles are the muscles of your abs and back. Core strength refers to their ability to support your spine and keep your body stable and balanced. Therefore, it too, trains the body for enhanced fuctional movement.
Planks are those exercises that help strengthen your core in the integrated fashion mentioned above. They most specifically target and strengthen the transverse abdominis muscle, the deepest of the abdominal muscles which wraps around your spine for protection.
The core is made up of other muscles too (external obliques, internal obliques, rectus abdominis, and erector spinae) however, I find that planks work the transverse abdominis muscle most effectively.
You may also be interested in knowing that the bike manuever effectively targets the obliques, crunches effectively target the rectus abdominis, and the superman variations effectively target the erector spinae. While all muscles of the abdominals are worked whenever you do any abdominal exercise, these particular exercises have been proven to most specifically engage these areas of the abdominals.
For a complete and balanced core/abdominal routine, be sure to include these exercises (or variations of them) in your core workouts.
Hope this helps
