I have a friend of a friend who needs blood platelets. First, what's the difference between giving blood and giving blood platelets? What type of effect does this have on the body as far as recooperating? I seem to remember reading somewhere it can take a couple weeks or more for the body to fully recover. I have no problem with needles and I'm more than happy to give my blood if it helps somebody but I don't want it to effect my athletic performance. I have a century coming up this weekend and a triathlon the following weekend. How will giving blood or blood platelets affect my body in endurance events a week or two later?