Start with a mini-speech: excellent entrepreneurs easily give a thirty second pitch describing their business; others struggle to explain their work in an hour long meeting. The ability to give a concise and compelling explanation of your coaching services gives people a reason to hire a coach and to hire you instead of a competitor. Connecting on an emotional and logical level to engage people with what they will gain, rather than what you will offer, is essential.
Expand on the concept behind a great elevator speech to a public speaking engagement: coaching certification develops the core competencies of a coach and in the process expands your skills as a speaker. Specifically, in coaching certification you learn about working with different personalities, adjusting to different learning styles, and you learn powerful language. This means that as a Certified Professional Coach, you will have excellent tools for developing understanding and building rapport with the different personalities in an audience.  The language of a coach is motivational so it positively impacts the power of your message when speaking. Bottom line: coach training enhances your skills and process so you are presenting yourself with poise and confidence.
As a side note: as a coach, public speaking is one of your most powerful marketing tools because you demonstrate expertise and connect with your audience.
Expanding your skills through an ICF-approved coach training is an investment in yourself that will take you to the next level as a public speaker.