Maybe seems like a strange thing to post on a running website, but I just came across this fairly well-written examination of supplements from the South African Rugby Assoc, and thought it was quite relevant to all sorts of athletes. Myself, I've all but given up on supplements and can't say that I notice any loss - an apple a day...
But if you are going to take suppliments then you should be informed. A lot of what they are after in this report is aimed at reducing the chance that their rugby players don't accidentally ingest banned substances. But they also say interesting things about legal supplements. In particular that supplements aren't necessary for most athletes. However the report is somewhat positive on whey. Remember, tho, that the typical rugby player is typically bulkier than most runners and so has higher protein needs.
You can find the report at:
A few quotes:
Supplements should not be used where nutrient needs can be met by normal foods and they cannot
compensate for poor dietary choices (32). Good food choices, on the other hand, do not compensate
for an absence of talent, motivation, or a lack of training, but will help players maximise their potential.
There are still many unanswered questions about the exact mechanisms and long-term safety and
side-effects of creatine