hat's the issue. As the concentrations checked were not really equivocal to conditions in the human body, it's theoretical for most people. If you dose at 450mg+ of caffeine on a regular basis, you have a slightly more fundamental and serious problem.
Massive amounts (truly enormous) of caffeine essentially trick the body into oxidising its phosphate stores, i.e. using up creatine if this is in ready supply. The issue with creatine, regardlyess, is that the effect on power output requires combining with carbohydrate to be effective, as otherwise the athlete/bodybuilder just holds water.