Where does one get PRACTICAL training for certification?

by Lisa
(San Francisco)

I'm looking into becoming a personal trainer, but am a little confused. There are many certification programs, and I have a fairly good idea of those that are most accepted by "the industry", but I'm unclear as to where one gets the actual practical physical training.

Sure, I exercise a lot, take self-defense, and am generally pretty fit. But I certainly don't believe I have the expertise to safely instruct others. And I don't see how reading a book or looking at illustrations are going to show me that, either.

I do know some trainers, and with one exception, they all began teaching exercise classes/training before certification was required, and got practical experience that way (and are now certified, of course). They all had a background in sports or dance, too.

The one exception attended the NPTI, which is very expensive.
So where does one get that practical experience?

Thanks!