Thanks for the question. You look for a fit trainer. If I wasn’t fit, I wouldn’t feel right about promoting wellness. I feel it is the highest calling for a Personal Trainer to be what he/she is asking her clients to be.
In addition, they must be certified by a National Certification like ACE, NCSM or ACSM. The tests these trainers take are very difficult and take a great deal of preparation and knowledge about the human body. For example, only 50% of the people that take the ACE Certification pass it the first time.
Finally, yes, they must be professionals who have a passion for fitness!