When To Donate Blood So You Don’t Screw Up Your Workout Routine

When To Donate Blood So You Don’t Screw Up Your Workout Routine

Giving blood is a great way to help others, but what happens when you show up to your next workout low on blood? Some aspects of fitness bounce back quickly, but you might want to put off any races or competitions for a few weeks.

Photo by Tom

Blood donation groups advise against heavy exercise the same day you donate, to avoid reopening the needle wound and because you may feel dizzy or faint from low blood pressure.

Plasma, the watery part of your blood, will return to normal levels within a few days. (You can help this happen faster by drinking lots of fluids, not just at the blood drive but for the next day or two). A study of cyclists who donated only the plasma portion of their blood showed that they didn’t last as long on an endurance ride the same day they donated, but were back to normal two days later.

Red blood cells take longer to regenerate. These cells carry oxygen from your lungs to your muscles, so when you’re low on red cells, aerobic performance suffers. The same study of cyclists also looked at the effects of donating whole blood on VO2max, a measure of how much oxygen their body could use at one time. It’s one measure of aerobic fitness. They found that the cyclists’ VO2max dropped by 15% on the day of donation, but by a week later was only 7% below normal.

How long does the effect last? One study that used recreational athletes found that they were exercising at normal levels three weeks after donation. Another, done more recently, showed that the men in the study (who all donated blood on a regular basis) were back to their pre-donation fitness level by two weeks, even though tests showed that their red cells were still a little low. That result led the authors to recommend waiting two weeks or more before you expect your best performance. The exact amount of time will probably vary from person to person.

If you race or compete regularly, your best bet may be to donate blood after a race, when you’re taking a few days or weeks of recovery, and when you know your next competition is several weeks away.

How Donating Blood Impacts Your Training and Racing (And 4 Strategies to Mitigate the Impact) [RunnersConnect]


  • I have an issue with the red cross. Even if you are a long term regular donor, if you foget to make a booking after a donation, they never bother to contact you ever.
    I’ve met a number of donors who presumed that there was some reason they were never contacted again.
    Must be something the red cross have not considered, can’t afford to do, or legally can’t do.
    they have an sms system they could send a simple reminder to rebook with say if you haven’t donated 3-6 months.

    • They could just use the dentist method: Book your next appointment before you leave the clinic, and then send a reminder a week or two before it’s due. If it takes effort to cancel, you’re much more inclined to actually turn up.
      (of course maybe they want people to do it by choice and not out of obligation. The dentist method works, but I resent them a bit for it)

  • It might be worth checking in with the blood bank to check the details on your account. I started donating regularly again last year and recently when I was in one of the nurses did a quick check of my details, for some reason my donor record had been accidently set to ‘do not contact’.

    I asked her to change it and since then they often give me a reminder call if I haven’t gone for a while or if they are low on my blood type.

    Also they do ask you to make your next appointment every time you go in, in fact they do it the moment you check in at the desk. They also send you sms reminders a couple of days before so you remember your appointment and when you should make sure to drink water.

    They also have a really great call centre where you can call to make an appointment at any time of the day or you can use their on-line book in service. They are really good at helping find an appointment that suits you.

  • I agree with maxamillion, I’m never asked to book in again before or after I donate. I get calls where they don’t leave a message when it’s time to donate again, which is kinda rude and also ineffective. A V/M or text would be far easier.
    Every time I book in is because I have made a conscious decision to organise it again.

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