I've been donating blood for many years in both Denmark and in the UK. I've also been involved in an interval-study over a couple of years to find out more about, how often one can donate safely. You can read more about the study and how my body reacted here.
I like donating blood and as long as I'm not a professional runner, I'm more than happy to share a pint of blood once in a while to those in need!
I have found a few links describing how long time a body normally would take to recover from donating a pint of blood. A website from NHS [National Health Service, UK] state that "most people's haemoglobin levels are back to normal after 6 to 12 weeks". So if you have a race coming up, and you are aiming for a PB, then you should probably wait until after the race to donate, as it affects the transport of oxygen in your body, which affects your performance.
American Red Cross states:
"How long will it take to replenish the pint of blood I donate? The plasma from your donation is replaced within about 24 hours. Red cells need about four to six weeks for complete replacement..."
Another site from RunnersWorld.com state that it takes about 60 days for a full recovery from donating blood (only about a day or two if you donate platelets):
"About one-third of that volume is red blood cells and the rest is mostly water. The water is replaced within the day as long as you get plenty of fluids, but the red blood cell mass replacement can take about two months. If you are well trained, you will not notice the drop in hemoglobin level at rest, or even with light to moderate exercise. When you push toward your training or race threshold, the lower red cell mass will become apparent."
And it also states:
"recommend giving yourself a couple of days off after donating to regain your fluid volume before resuming your training. Wait at least a month before running a serious race, meaning a marathon or fast-paced shorter race. Two months would be safest, especially if you plan to run at an altitude that is higher than where you usually live and train."
So all in all, don't expect to be able to perform your right after donating and give your body time to recover. Every body reacts and recovers differently from donating. Listen to your body - what does is say?
Based on my previous experience of being low in iron levels and the fact that I'm 99% vegetarian, I have started taking iron supplements to ensure that my levels doesn't drop too much and that I have a source of iron to recover after donating.
Some sources of Iron-rich foods include (Source: NHS):
- dark-green leafy vegetables, such as watercress and curly kale
- iron-fortified cereals or bread
- brown rice
- pulses and beans
- nuts and seeds
- white and red meat
- dried fruit, such as dried apricots, prunes and raisins
- tea and coffee
- calcium – found in dairy products, such as milk
- antacids and proton pump inhibitors (PPIs) – medications used to relieve indigestion
- wholegrain cereals – although wholegrains are a good source of iron themselves, they contain phytic acid, which can stop your body absorbing iron from other foods and pills
I hope this gave you a bit of insight to how your body reacts to donating blood. I can definitely tell that running after donating is harder, and my heart rate definitely increases as the heart will have to work harder to transport the same amount of oxygen round the body as before donating. Hence I try to keep the first couple of sessions at low intensity to give my body a break and a change to recover, and then pick up speed and/or intensity as it gets back to towards normal levels.
Until next time - see ya all out there :-)