The combination of an effortless low breath and a fully relaxed throat allows the vocal folds to vibrate freely. The exercises mentioned on this part of the video aid in training the tongue to remain gently arched upward and forward, while relaxing the back of the throat.
In this course, Artist Eric Arceneaux gives 4 video lessons on Basic Vocal Warm-Up Routines. The key, as with any exercise plan, is to stick to it and do it everyday. Please visit this site for more information: http://budurl.com/powerseries.