Earlier today, Ari over at Run Ansky Run asked me a question about donating blood and running that I found rather intriguing. So instead of writing a long drawn out e-mail or comment that might seem rather inappropriate for such a simple question, I’ve decided to answer it here in an attempt to educate the masses who might be similarly interested in the topic.
He asks – Laminator, I gave blood today and I am scheduled for speedwork tomorrow. Is is OK for me to do an intense workout, such as speedwork, 24 hours after giving blood?
First off, on behalf of those that may need your blood for whatever reason, thank you for donating. As every health professional knows, there’s a shortage of blood in the NYS Blood Bank right now so every little bit helps.
Now to tackle your question on more than a cursory level, let us review the physiologic effects of giving blood. Typically, 450cc of fresh blood is removed during a standard round of blood donation. This blood that is taken away is composed of multiple different fractions – packed red cells, white cells, and plasma. Of particular interest to the athlete are the red blood cells (RBCs) which are responsible for oxygen transport and delivery (via hemoglobin) and plasma which makes up the bulk of a given volume of blood. According to different studies, plasma volume drops 7-15% after standard blood donation, but returns to normal levels within 12-24 hours (depending on the rate of oral rehydration after the donation). RBCs on the other hand can take up to 3-4 weeks to return to normal levels (the production of RBC production in the bone marrow is a slow and tedious process). So although the initial recovery is relatively quick (within 24 hours), there will a noticeable drop in maximal performance for at least two weeks after. Because of this, some coaches of competitive runners will discourage their athletes from giving blood in season or during peak training.
So, my advice to you, my dear friend, is to hydrate liberally immediately after the blood donation to replenish your plasma volume as quickly as possible. Stack up on your vitamins (Iron & B12) if you are into supplements. Try to decrease the level of your physical exertion for at least 24 hours to allow for adequate physical recovery. If you are going to run or engage in exercise, limit the effort to a moderate intensity level and keep an eye out for signs of physical decompensation (such as dizziness, lightheadedness, nausea, extreme fatigue, etc). Listen to your body and stop immediately if you should experience any of these symptoms. As is, you will find that your heart rate is a bit higher and the effort a bit harder to maintain than you are used to even just running at a slow pace so be careful out there (especially in this hot and humid weather).
Thanks for the question. For those who want to read more information from a more authoratative source than I (including how some elite athletes use this technique in reverse to booster their performance on race day), check out this article.
Happy running all!