Oh and to actually sort of make a point rather than just ramble (:P) creatine is only used as an energy source in the ATP CP system.

Which is not used during endurance events.

I'm also gonna make it clear to any one reading (no one in particular, just feel I have to say it ) that it's not enough to just have the Energy sources in your body, you need to train your body to use them efficiently and train it so it adapts and holds a larger threshold of the thresholds/deposits of energy sources (fat, Glycogen (Complex carbs which are then broken down into simple carbs (glucose, either by digestion or simply already intaken as glucose) and then turned into Glycogen) and protien (though the body doesn't really use protien for energy as it has to be converted into fat which is inefficient) I don't know if Creatine Phosphate if classes as a protien or not (if it is, it's the only protien that is worth thinking about as an energy source )