Just imagine yourself in that empty chair. Does the camera, studio lights, and or reporter intimidate you? Can you present your research in a clear concise manner without relying on jargon? Could you explain what you do and why it matters to an 11 year old? Strong communication skills are important and nothing beats practice.
While some people say that public speaking is the most feared thing to do; I think speaking in front of the camera is. It is important that as a graduate student you can master both skills because you are building a career that involves public speaking. You are becoming an expert at something that might require you to be interviewed by a television reporter. With a PhD, you will be expected to present your research at your professional organizational meetings. You will be required to conduct a “job talk” if you hope to be eventually employed.