I was due to donate blood February 14th, but didn't, because I had scheduled a Century the 11th and either an organized or personal 200k the 25th, and a 400k March 11th. This is the only time in many years I have held off on donating due to an athletic event, though there is always heated discussion on the Ultrarunning list about what's the best protocol. Heck, I've run 5 miles on a hot afternoon the same day I gave blood, and felt _nothing_. (You could argue that running, at my pace, is NOT a strenuous activity!)
But really, I think I probably would have been ok. It'd be three and a half weeks out from the 400k. I wonder what percentage of the red cells would be back by then?
On a Podcast I was listening to yesterday, they were talking about Tyler Hamilton and his accused blood doping, saying his blood had been found to have someone else's red cells in it. I hadn't actually thought "they" (not saying he did it- I would like to believe he did not) took out their own red cells, stored them, grew more, then put their own back in. It never occured to me that it could be someone else's cells. It kind of grossed me out, but really, why should it? That's what blood donation is all about. Weird.
It amuses me to carry my electrolyte caps in a Procrit (epoetin) tin that I got at work as a promotion- it had mints in it.
That's cool that you can tell a performance difference like that.
Nanci