Yesterday, just a few hours after an easy run I donated a pint of blood. It feels great knowing my blood will help some sick people, unless the blood drive I went to was a front for some enterprising vampires. I’ve done this many times before, so it was no big deal, though I do wonder at times if donating blood affects athletic performance. And how long it takes for the blood(especially hemoglobin) to be replenished.
Blood is made up of many different components. Blood plasma can be restored in as little as 24 hours, so long as the donor stays well-hydrated. Hemoglobin(or haemoglobin, for my British friends), on the other hand, can take 4 to 6 weeks to be fully replenished, as long as you get enough iron and protein. So if my athletic performance is going to suffer at all, it will suffer for a few weeks at most.
For those of you who want a more in depth look at this issue, I found this interesting article over on Runnersweb: Science of Sport: The Effects of Blood Donation on Endurance Athletes
Rest assured, the effect is rarely big, and it depends on the individual. After donating, drink plenty of mineral rich fluids and eat a lot of iron rich food, which is what I am currently doing. Avoid alcohol and caffeine. I encourage everyone, so long as you qualify, athlete or non-athlete, to donate your blood to help those in need.