You fill up with pasta before running a marathon, so...

I'm getting a bit confused by this "drugs in athletics" business.  It all seems to hinge on blood-doping, which I think it can be argued is not doping at all.  If I understand it correctly, it involves blood being taken from a competitor a couple of months before a competition, and then re-injected a few days before said competition.  The competitor's body will have made up for the blood taken in the interim, so the re-injection will increase the number of red blood cells, which enables the competitor to take in more oxygen and thus keep going longer.  So, performance enhancing, which is why it's considered unacceptable, but it's the competitor's own blood - it's not altered or added to in any way, so how is this different from eating a specific diet, or even following a specific exercise regime with the goal of boosting your energy levels? I seem to remember it was Vladimir Kuts (or his medical team) who first developed the technique in the 50s, so it's hardly new.  If the blood is enhanced or treated in any way, then that's a different matter, but simply giving an athlete some of his/her own blood back?  Not sure!