Whats the hardest thing about being a personal trainer?

In my opinion, working long hours. Early mornings, evenings, and weekends, especially if you are your personal training business. If you are not leveraging your time properly, then you must work lots of hours of one on one training to make a significant income. The burnout rate can be high if you don't other profit centers, and implement leverage into your business.

I think that is very true. I think it's also true that a lot of personal trainers overlook a wholistic approach to fitness many times. Employing meaningless tactics instead of useful knowledge.

The hardest part is working in any type of corporate setting. There is always the prospect that you are training in an environment where the overall goals are anti-thetical or contrary in interest to the people taking up the training programs. The person wants to lose weight, the club does not want the person to lose weight, in order that they will stay and spend more money. I think some trainers struggle with this, i know I did for a short period.