@iwillbite @p After days/weeks of sufficient creatine dosage, it gives you a 5-15% boost in high intensive, repetitive anaerobic work (such as lifting weights).
As it allows slightly more muscle damage before you become totally exhausted, it allows the possibility of slightly bigger muscles on healing (but realistically, many stop when they've think that they've done enough, not when they can do no more - in the former case, creatine won't do much).