Excellent post and very big plus 1 from me. As a trainer I see a lot of what you're describing and the lack of understanding from personal trainers is very high. This unfortunately makes them dangerous. Ask your potential trainer questions. What are your qualifications, what can you tell me about X? Who do you like to train? Who can you train. How long have you been training. Can you do a pull up? That's a big one. If you're a trainer and you can't do one pull up, then you shouldn't be training.