Blood donation and sport performance



Iron supplementation helps limit the impact of blood donation on sport performance. This is reassuring news for athletes, whose donations are so valuable for the blood supply.

Blood donation is an act of solidarity that is crucial to our healthcare. Every year in Belgium more than 500,000 units of blood are used to save lives. One person in seven needs blood at some point in their lives, yet only one in ten actually donates blood. Thus it’s vital for blood collection services such as Rode Kruis Vlaanderen to be able to count on regular and healthy donors. Amateur athletes are especially valuable because they are generally in excellent health.

Muscles in need of oxygen

Especially for athletes, however, donating blood leads to a temporary deficit in the body which can have various impacts. Recovery time is necessary, the duration of which depends on the quantity and type of donation (platelets, plasma, whole blood). After the donation of whole blood, the haemoglobin level and thus the iron concentration in the body drops, resulting in reduced transport of oxygen to organs and muscles. Less oxygen in muscles means poorer performance. Obviously, this can be a detriment to athletes.

Providing transparent information

Hence Rode Kruis Vlaanderen’s initiative to launch a scientific study on the effect of repeated blood donations on sport performance, and on the effect of taking iron supplements to compensate for performance decline. The goal is to provide clear, transparent and scientific information to blood donors. ‘To date, little on blood donation effects has been scientifically analysed and validated,’ explains Louise Deldicque, a professor and researcher at the UCLouvain Exercise Physiology and Biochemistry Laboratory and the Centre for Clinical Investigation in Nutrition (CICN). ‘This type of study will make it possible to make recommendations based on scientific conclusions.’

Iron supplements to the rescue

Study results showed that iron supplementation after repeated blood donations can limit their impact on sport performance. ‘A 20 mg intake of iron is sufficient to preserve muscle function in athletes after a blood donation,’ Prof. Deldicque says. ‘In total, we double the recommended daily dose, which is certainly not huge.’ However, blood measurements show the supplement has no effect on blood iron reserves in the form of ferritin, the protein that stores iron and releases it when needes. ‘In terms of good muscle function and the action of iron on the muscle tissue, we have achieved the desired effect with the supplementation, but this doesn’t come about through a rectified concentration of ferritin in the blood.’

What happens in muscle tissue after taking iron supplements? How can one limit the drop in ferritin concentration following blood donations? Could limiting donations to plasma (blood without red blood cells) avoid altering blood iron content? Rode Kruis Vlaanderen addresses such questions in order to further document the effects of regular blood donations and how to limit their impact on donors.

Planning donations

Prof. Deldicque’s study also highlighted the duration of the negative effect of a blood donation on sport performance. ‘Sport performance is clearly impaired for one to two weeks,’ she says. ‘However, after a month, athletes completely recover their abilities.’ These data will enable donors to be well informed and able to plan their blood donations according to their sport activities. ‘For example, a person preparing for the Brussels 20K will avoid giving blood during May if they want to perform to the best of their physical abilities.’ Prof. Deldicque has already begun a new study to analyse the side effects of plasma donation.

Audrey Binet

Published on November 02, 2020