Women's Tennis Battles "Grunt Work"

According to certified athletic trainer Ralph Reiff, grunting is used by players as "sort of a mental cue" to follow through in the process of bearing down and activating the body's core muscles, and when players go through with hitting a shot, it becomes part of a comfort level and aid in dealing with performance anxiety.
Read more at http://espn.go.com/espn/otl/story/_/id/8103913/women-tennis-plans-eliminate-excessive-grunting-next-generation-players