Blood donation is one of the most important ways to share your good health with others. Each unit of blood you donate can help up to three people in need of blood or blood products. However, you might be concerned about working out after giving blood.
If you've donated blood, plan to take a break from exercise for the remainder of the day to allow your body to recover.
Blood collection sites typically recommend you refrain from vigorous exercise and heavy lifting until the day after your donation. Specific recommendations may vary depending on the type of blood donation you've made and the intensity of your physical activity.
Read more: The Best Foods to Eat After Giving Blood
Understanding Blood Donation
Your blood consists of a fluid portion called plasma and formed elements, including red and white blood cells and platelets. Your red blood cells carry oxygen from your lungs to your body, including your muscles.
When you donate a single unit of blood, you typically lose roughly 10 percent of your total blood volume, according to the National Academy of Sports Medicine. The fluid portion is replaced very quickly, typically within a day. Complete replenishment of the red blood cells takes more time, typically four to six weeks.
The reduction in red blood cells usually doesn't interfere with your ability to perform moderate exercise. If you participate in vigorous exercise or are an athlete in training, however, you might notice a temporary reduction in performance due to the reduced oxygen-carrying capacity of your blood.
Working Out After Giving Blood
The American Red Cross recommends that regular blood donors avoid strenuous exercise and heavy lifting for the remainder of the day of the donation. This is primarily to give your body a chance to replenish the fluid portion of the blood donated. While strenuous exercise should be avoided, you don't have to sit in a chair all day.
After you've had a chance to drink some fluids, you might enjoy some light to moderate activity if you feel up to it, such as a brisk walk, a swim or a casual bike ride. Drinking plenty of fluids before and after your donation helps you avoid dehydration. The American Red Cross recommends drinking an extra 32 ounces.
You may also find it helpful to ingest some carbohydrates immediately after you give blood. Most blood donation sites offer beverages and snacks to donors.
If you are an athlete or participate in vigorous training, your aerobic performance may temporarily be affected after blood donation. Endurance training relies on your body's ability to carry and use oxygen to generate energy. There can be negative effects of blood donation on exercise performance. Blood donation temporarily reduces your blood volume, for about a day.
Although some individual research studies have reported decreased exercise capacity following blood donation, a research review published in April 2019 by PLOS One found that among pooled studies VO2 max, or maximal oxygen uptake, is not significantly reduced 24 to 48 hours after blood donation.
Read more: What to Eat After You Lose Blood
Exercise with Caution
Recommendations about exercise after blood donation may vary, depending on the type of donation you're making. For example, if you're making a double red cell donation — donating twice the usual amount of red blood cells — you might be advised to avoid strenuous exercise for a longer period.
If you feel dizzy or lightheaded during or after post-donation exercise, sit or lie down until you feel better. Make sure you're drinking plenty of fluids and contact your donation center or health care provider if you are concerned about any symptoms you experience after blood donation.
Is This an Emergency?
- American Red Cross: "Donation FAQs"
- National Academy of Sports Medicine: "Donating Blood and Exercise: What Athletes Should Know"
- PLOS One: "The Acute Effects of Whole Blood Donation on Cardiorespiratory and Haematological Factors in Exercise: A Systematic Review"
- American Red Cross: Tips for a Successful Donation