Moving from thinking about starting an exercise program to joining a club, working with a trainer to set goals, and showing up for workouts is an example of which model of behavior change?

The correct answer is: Transtheoretical model.

Explanation:

The transtheoretical model of behavior change is a model of therapy that gives element to an individual to engage in modifying unhealthy behaviors in order to change them for healthier ones by providing with specific plans and strategies.

This model values change, which reflects in the different stages that a particular individual has to go through before he si able to elicit newer and healthier behaviors.

In this particular case, the example of

1 - Moving from thinking about starting an exercise program to joining a club,

2 - working with a trainer to set goals,

3 - and showing up for workouts

is an example of Transtheoretical model of behavior.