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Runners: what to consider before donating blood

How runners can safely give blood without compromising their training

Arm of a donor donating blood at hemotransfusion station

As Canada continues to face a blood shortage, runners might find themselves wondering if they should donate. However, if you’ve found yourself questioning if giving blood could disrupt your training, your hunch is correct. Donating blood is a great thing to do, and should by no means be discouraged, but there are a few additional considerations for runners. Here are some tips to ensure you’re donating at a time that makes sense for you and your goals. 

Blood donation affects performance

After blood loss, an individual’s blood volume (and red blood cell count) decreases, which by extension, reduces your body’s oxygen-carrying capacity. This is significant for runners as oxygen delivery is a key factor in aerobic performance. When your muscles are low on oxygen, their performance is inhibited. 

When should you donate?

Studies show that the body will restore blood volume within three days of donation, and most lingering performance inhibitors should be cleared up within three weeks. However, when it comes to overall hemoglobin levels, they can take up to six weeks to return to normal. While most runners wouldn’t notice the temporary decrease day to day, it could have an impact on a big effort, like a marathon.

With this in mind, the ideal time to donate is out of your competition period. It’s recommended to avoid strenuous exercise for 24 hours after donation, but if you’re in a training phase, it’s safe to resume your normal routine a day later. When it comes to racing, however, try to avoid giving blood within month of the big day. Your results (and recovery) will thank you.

For more information on blood donation, see here.

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