Originally Posted by Mister Pokémon
If you mean levels, I guess he trains at the second Elite 4, which you can battle after getting Ruby and Sapphire for Celio. By the way he posted his team, I guess he doesn't EV-train, so it isn't as good as it can be.
EV training takes longer, but reaps much greater rewards. Why train your team to level 100 if they aren't at their full potential?