I think this can be good, aka training with clients but only if you make it of higher value... The delivery should not as point blank in their face, but the idea there is this. "I am the trainer, and a person that you look up to and who motivates you. Working out with me is a privilege, and one I only share my best clientele.
Then it is more of a reward than something you would discount.
That or if asked when or if they can train with you, you explain that is an opportunity that is earned through hard work and is also slightly more expensive as it takes your focus away from yourself during training. Then if they still want it the value is built up for them, and they are getting an "Experience" for their money not just a session.
TheMovement, how is it not ethical? I mean if the communication is open, and it is not looked at or presented as a regular session and the client WANTS to work out with you for their sessions? How is it unethical to do so?
Obviously this wouldn't work in training for a competition or something but in general training one can program around the clients needs while keeping it also applicable to themselves. Is it ideal for the trainers training, no not at all but the client will more than likely get one of the best workouts of their life. Working out with someone I really respect makes me work harder and try to perform better.