Agreeing with Brock_Lee on this. When I was playing through FireRed, it took a lot of training to get my team strong enough to defeat the Elite. It was the first time that I actually had to train for a while before the challenge. And even after all that training, I still had some difficulties.
It was the same thing with my Pearl game. That one, however, was a bit easier after training. I wasn't down to my last Pokemon while facing the Champion.