[Closed] Creatine/Whey Protein - Worth it?

I'm starting to take this cycling stuff a little bit more seriously now I have found that cycling to work and back saves me a fair amount of money each month. I'm also slowly getting fitter, but I keep seeing the various muscle supplements in the sport section of the local Tesco and I keep wondering if they could really help with increasing both strength and stamina when I'm out and about.

So, has anyone used either of the above as part of a training schedule? Do they work? Are they really worth spending the savings on petrol on?