When it comes to strength training, there are a number of exercises that are effective. When it comes to get a stronger core, however, few exercises are going to be more effective than the plank. This is an exercise that looks easy, but people find that it is difficult to do even 10 to 20 seconds at first. This is because of how this exercise is working your core muscles and helping you to create muscles that are strong and solid.
Nora Tobin published an excellent article over at mindbodygreen.com that will help you to decide to incorporate planks into your regular exercise routine. Check out the link below to learn more about the benefits of this exercise.