A universal tendency in public speaking is for people to try to fit too much into their talks. Presentation coaching helps you edit and tighten your content for maximum effect. That is especially necessary when you are given less time than usual to speak.
Here is an example from TEDxGreenville. Prasanna Eswara, in first considering his talk, began with slides that accompanied a presentaion that he had given previously, but in which he had an hour to speak. However, for his TED talk he was only allowed five minutes, calling for a wholly different andmuch more concise presentation.
Here is his initial PowerPoint which inluded 35 slides, animation, and was content-heavy even for an hour-long talk: initial PowerPoint
By cutting his content down to its essence, Prasanna was able to give the audience a strong speech in his allotted time: