Well, it's less about the fighting itself, especially in the beginning, and more about how much stronger it's made him. A good measurement of if he's gotten enough is if he's managed to learn any new moves so far. His starting array of attacks isn't very well-rounded or powerful, and he's going to be very eager to learn new, more useful abilities.

Of course, there's also the type of Pokemon to consider. Absol are said to be able to predict disasters... he may want to get stronger quickly because he senses something approaching.