I agree with what Brendan and Anthro said as well.
Are you passionate about training other people? Do you have any experience teaching? If so, what did you think of it? Were you good at it?
All of those questions are very important. There are enough half assed trainers out there who give those of us who are serious bad names. If you aren't truly passionate about it, then I'd suggest that you find something that you really are passionate about and go after it.
I'm not saying that you wouldn't make a good trainer, or that you might not be better than a lot of the trainers out there. Just that, training other people can be tough.
You've got to be able to adjust to multiple personality types (not the disease, just that there are different personality types out there), different types of motivation, different goals, different work ethics, injuries, age, etc... There's really a lot more to it than most people realize and if you're really not passionate about it, you may come away with a bad taste in your mouth (as well as leaving a bad taste in the mouths of some of your clients).
If it is something that you think you really want to pursue, then by all means go for it. And try to educate yourself as much as possible as well. You'll probably have to get some sort of certification, and you'll soon realize that most of the major certification orgs are, at least a little, behind the rest of the industry.
So, you might find yourself just answering questions with the answers that you know those orgs want to hear (yet knowing that those answers may be incorrect). But just suck it up, get the certificate and then you can do what you know is right when you get out into the field.
Good luck and good training,