Blood Transfusion and Athletic Performance

Mike Corefield May 2007

 

I recently gave blood for the first time - unusual you may think for a doctor but my attempts in the past had always been thwarted. I knew that theoretically it might impact on my running but conventional wisdom said it would be brief. Five days after giving my blood I did a Sunday run at The Lookout and was definitely off the pace and had to drop off the group - I felt heavy legged and more breathless than usual. The following week a Wednesday night had me running again and I felt reasonable for 30 minutes then I ran out of energy and had my worst run for ages - things seem to be getting worse! I decided to see what I could find out about it.

The National Blood Transfusion service uses athletes to promote its service such as Mark Lewis Francis but there is no information on its web site about performance other than advice that you can go back to work immediately after giving blood. I found a question on Runners Web Forum which provoked a huge number of responses from runners most saying that they took several weeks to recover and many quoted the increase in their running times.

When you donate approximately 450 mls of blood is taken - this consists of 55% fluid and 45% cells. The latter is made up almost exclusively of red cells which contain haemoglobin (Hb) - the molecule that transports oxygen and carbon dioxide around the body. The fluid loss is replaced within 24 -48hrs. The Hb level falls 1-2g/dl from its normal range of 11.5 - 18.5 g/dl representing a loss of 7-13%. This is made up with in 3-4 weeks.

There is actually little information about how blood donation affects performance - though I did find one article at:-

http://www.physsportsmed.com/issues/2001/06_01/news.htm

This article suggests that maximal performance is affected - more for endurance athletes especially the elite and in older runners (over 50 like me!) who take longer to recover from most things! It also suggested that power athletes (and I would include sprinters like Lewis Francis in this group) would not notice any effect. However there was no longer term detrimental effect. The experience of the Runners Web members would suggest that donation could affect you for up to 4 weeks and if you were a regular donor then it might be longer.

 

There are a lot of good reasons for giving blood and runners are amongst the healthy members of society and probably in a better position than most to donate thus I would strongly recommend it, but I would suggest anyone with an important race coming up in the next month consider carefully whether to postpone it. I will continue to give blood in the future and would encourage all of you to do the same.