Holding the standard plank for ten seconds or longer is useless according to Dr. Stuart McGill. Unfortunately, many people still try to do planks for time.
A better way to progress this core exercise? Make it harder. The cable plank press will help you take your core strength to the next level, and you'll even build some extra upper-body muscle.
As I sit here in the airport reflecting on my recent trip, I'm once again exposed to the reality that most Americans just don't move. At least not under their own power. Mostly we just like to sit motionless.