athletic supplements?

One thing I've observed since I began running is that athletes tend to be fairly obsessed with supplements and powders. They make protein shakes with this or that vitamin or mineral and claim they've found the secret to building muscles or repairing tissue. Personally I find it all to be just a bit strange... I mean, I take a multivitamin but anything beyond that feels like a heartbeat away from steroids or creatine monohydrate or some other ethically fuzzy product.