1.  What's your educational background? 

The answer to this question should come in the form of an exercise science degree.  Now, there are some good trainers that have a degree in something else, but they are few and far between.

2.  Who are you certified through?

It's still amazing to me when I find trainers that aren't certified.  While I firmly believe certifications are only a "piece of paper", they provide some indication of how serious the trainer is about what he/she does.

3.  How many years of experience do you have?

Experience is a major factor when selecting a personal trainer.  That's right, I'm contradicting my above statement a little bit, but hear me out.  Experience will often be more important than certifications and schooling.  The latter is necessary to establish a solid foundation, but provides little to the actual application.  As always, there are some exceptions to the rule.

4.  Do the results sound unrealistic?

Statements like, "I can help you lose 30lbs in 2 weeks" should be an instant "red flag".  You want a trainer that's honest with you throughout the training process.  If they give you unrealistic expectations, what happens down the line?

Personally, I never tell any prospect how much they'll lose within a specific time frame.  There are just too many factors that go into it.  I d

o, however, promise positive results if they adhere to the program.  24/7 compliance always produces faster results. 

5.  Is he/she professional?

It sounds really basic, but many personal trainers aren't the least bit professional about their business.  You want to make an investment with someone who's just as serious and committed to your achievements as you are.

6.  Does he/she pay attention to current clientele?

This one could be a bit tricky because you have to be present when he/she's working with someone else.  Watch to see if he/she is paying attention to his/her client.  This is another thing that would seem a "no brainer", but a lot of trainers don't pay any attention to technique, repetitions, etc.  To me, this indicates lack of interest in the client. 

7.  Does he/she write anything down?

You'd think that all trainers would write stuff down.  Unfortunately, many don't and could be winging the consultation, training session, etc.  How does this bode for reaching your fitness goals?  Thing's probably aren't going to turn out the way you'd hoped.

8.  Is there client/trainer chemistry?

No, I don't mean it in that way.  What I'm saying is do you think you can work well with this individual.  Compatability is a major factor in making the experience more enjoyable and effective for the both of you.  It could possibly be the most important factor in selecting a personal trainer.