Gotta Run: Here’s what happens to your body when you give blood

Published 12:00 am Saturday, December 17, 2022

Giving blood is always needed, and there are lots of blood drives going on during the holiday season. One of the concerns for some who don’t give is they are unsure what will happen with the body, especially if they exercise regularly. I’ve been giving for many years and plan to continue for as long as I can.

Giving blood is especially easy these days since you can look at all of the upcoming blood drives within a specified area at Once you schedule to give, then you will get the opportunity to do the rapid test. It is a quick summary to make sure you are eligible to give currently and takes less than five minutes. You get a QR code to print or save on your phone to show the Red Cross volunteers upon arrival. Or you can choose to do the quick summary when you check in.

You will also get a quick check for blood pressure, pulse, body temperature and iron upon arrival too, all useful in case you didn’t know about an issue. If all is well, you’ll go wait for the volunteer who will actually draw your blood. The blood draw takes from 5-15 minutes. Our running club has several competitive givers who time the process and try to shorten it if possible. Squeezing the little ball and being hydrated are helpful, especially if you want to get done quickly and move on to the snack table. You get a small gift from the Red Cross, and once listed, you will be notified about opportunities to do it again.

Donating blood is a noble act and helps save lives. Athletes and regular gym goers should not shy away from this opportunity due to fears of affecting performance levels. By following the recommendations and planning when you donate blood to suit your training program, you can help save lives just as you would hope others do if you need blood.

Here is what happens to the body when you give blood. Donating one pint of blood (the typical amount drawn during a whole blood donation) reduces blood volume by about one tenth. Since oxygen travels throughout your body via the bloodstream, having less blood on board can affect how you perform during your workouts. It only takes about a day for your body to replace the fluid portion of your blood, called plasma. It can take four to six weeks for red blood cells to reach their pre-donation levels, but several studies show there’s only a 24- to 48-hour dip in exercise performance after donation.

There’s a short-term dip in maximal oxygen update (how much oxygen people can inhale and use), but it seems to return to normal within a day or two.

“When testing elite athletes, their uptake, measured by what’s called VO2 max, might be down 3, 5 or even 8 percent compared with pre-donation levels. Most everyday athletes and fitness fans won’t notice any significant lingering effects after giving blood. For most of us, it’s not something you or I could sense after a couple of days.” said Dr. Jed Gorlin, vice president and medical director at Innovative Blood Resources in St. Paul, Minnesota.

And no matter what exercise you do or don’t do after donating blood, always listen to your body. If you notice any dizziness or lightheadedness, end your workout right there. Sit or lie down, wait for it to pass and then gradually get back up and get some fluids and food in you.

A few more good things happen, and I’ll address those next week. I’m scheduling to give blood this week and will report on that too, plus how I altered my running and other exercise to make it happen.

Our next race locally is the Bradshaw Financial Planning Resolution Run 5K at the Forum on Jan. 2. Look for it and more events at