Hi Melanie. The route that I’ve chosen is to first gain an “industry presence” through writing and publishing. To me, once you’ve gotten a few published articles or such out there, things begin to open up to you in all other media. With that industry recognition in hand, it helps of course to hone your presentation skills as well, before tackling industry presentations, so I think it is good to give seminars or presentations to lay-audiences on fitness topics of your choice (as a matter of fact, many of the industry organizations will ask about your prior presentations and may ask for a short video clip of one or two).
I hope this helps, and good luck!
Joanne’s and Kurt’s answers are excellent. You have to be able to clearly and completely describe why your level of expertise and knowledge in the topic(s) you want to present are unique and scientifically sound. Prepare a demo of your presentation(s).
If possible, attend as many conferences/conventions as you can to learn from those who are presenting. The IDEA World Fitness Convention (July, 2012). would be a good start.
I would suggest finding something that you are passionate about and becoming very good at it. Not only in a practical but a theoretical way too.
Attend the IDEA World convention and frequent the workshops of the presenters whose workshops are popular learn from their teaching style.
Learn all that you can about the industry. Take out membership to IDEA and read the articles written by industry leaders.
I wish you the best with your career.