My current fitness club requires that all personal trainers have at least a B.S. degree (almost all of them have a Masters) in fitness/exercise science, and have ASCM certification (at least, most of them have multiple certifications). Our spinning instructor has all of the above, as well as certification in spinning and is a life-long avid cyclist.

I've never seen such a high level of qualification required by a fitness club for their training staff - but my club IS medically based and is part of an Osteopathic hospital (the fitness club is a massive facility). Their primary focus is wellness, and they will even waive the initiation fee if your doctor officially prescribes exercise.

My last fitness club did not seem to really have any requirements, at all, for their training staff other than a willingness to work for X amount an hour. I am taking full advantage of the trainers, there are two I work with, but I doubt that I would have ever done that if they were less qualified. From what I can tell, there seems little consistency between club to club regarding this.