I think it varies. It depends on how many sessions inbetween without the PT that the person is working and if they are able to improve. Some people I'd imagine are just ablt to pick things up faster then others, some people lie to themselves and their trainers saying they want to improve but really don't (and so don't do as well) things like drinking (alcohol) the night before a session or overeating and then not being honest about either (yet being very obvious) can add obsticles. It really does depend on the person and how much effort they are willing to put in and how able they are.
And also depends on what their own goals are. Weight loss, stregnth, fitness... there are lots of goals and loads of variations on them- some goals are larger then others.
