While the internet loves to debate the importance of a personal trainer (surprising, I know -- arguing? On the internet?), I've always felt it to be helpful to engage in self-coaching. Although we don't NEED a personal trainer, we do need to take ownership for our own health. Notice the pronoun here in 1 Tim. 4:7:
You are to take responsibility for your own spiritual (and physical) health. You can't outsource that to the pastor or to the trainer at the gym. No one else is responsible for your spiritual or physical well being. "Train yourself," writes Paul. "Take time and trouble to keep yourself spiritually fit" is the way J. B. Phillips translates it. The Living Bible says, "Spend your time and energy in the exercise of keeping spiritually fit." And I love how the GNT puts it: "keep yourself in training."
These are areas that YOU are ultimately responsible for. No one else.