Blood Donation and Running

The more oxygen-rich blood available to your muscles, the faster and longer you can keep running!

So, If you do make the decision to donate blood, are there some things you should know before you go back to full training?

First some facts;

A recent study looked at the short-term effects of donating blood. Participants rode to exhaustion on a stationary bike before giving blood, & repeated the test two hours, two days, and seven days after the donation.

They analysed both time to exhaustion and maximum oxygen consumption and found VO2 max dropped by 15% and time to exhaustion decreased by 19% during the exercise test two hours after a blood donation.

VO2 max was still 7% lower than pre-donation levels at two and seven days post-donation.

Also in 2011 a study, suggested that VO2 max returns to normal (pre-test level) three weeks after the date of the donation.

When you give blood, specialised cells in the kidneys sense that the level of oxygen in the blood has decreased (due to the loss of red cells) and start secreting a protein that passes through the bloodstream until it reaches the bone marrow (which produces stem cells – the building blocks that the body uses to make the different blood cells – red cells, white cells and platelets).

This protein sends a message to the stem cells telling more of them to develop into red blood cells, rather than white cells or platelets, about 2 million new red cells are made every second, so it doesn’t take long to build up stores of them again.

There is an important link between your red cells and your health because its the red-coloured haemoglobin that carries the oxygen around your body to your muscles. This Haemoglobin contains iron, some of which is lost with each donation. So to compensate, iron absorption increases and your body utilises more of its stored iron. Iron deficiency can result in reduced haemoglobin levels, and eventually, if not treated, in iron deficiency called anaemia. This deficiency can make you feel fatigued, which will be exaggerated by exercise.

After a donation, most people’s haemoglobin levels are back to normal after 6 to 12 weeks.


Therefore you can see, blood donation will lead to a notable short-term drop in performance, but will return to normal after about three weeks, with the worst of the fatigue coming in that first week.

So if you’re a blood donor give yourself some days R&R and don’t plan a race for a couple of weeks if you’re chasing a PB.