Exercise and Donating Blood: What You Should Know by Guest Writer, Kenny Kline

Today's blog features content from guest writer, Kenny Kline. Thanks, Kenny, for your contribution to our blog!

Do you usually donate blood? As stated by the American Red Cross, there’s an American in need of blood every two seconds. This tends to about 41,000 blood donations per day.

Donating blood is an avenue for most people to help those in need. However, it is vital to know that blood donors need to take some precautions after donating so that their bodies can have time to recover. This includes not working out or exercising directly after you give blood.

What Happens After You Donate Blood?

Your body can replace the fluids and cells that were lost after you donated blood. Millions of your red cells are made and perish every second. When you donate blood, you lose multiple red cells, and your body will need to make more to replenish them.

Special cells located in the kidneys can discern that oxygen level in the blood has decreased (because of the loss of red cells) and starts to discharge a protein that will pass through your bloodstream until it has reached the bone marrow. 

The bone marrow will then produce stem cells -a building block that helps the body make different blood cells- white cells, red cells, and platelets. Moreover, the protein will send a message to the stem cells and direct them to develop red blood cells rather than platelets or white cells.

It is vital to know that your body can produce about 2  million newly created red cells every second. Hence, it will not take long to increase stores of them again.

Best Time To Give Blood

If you are an athlete or a gym rat that wants to give blood, you can freely do so. However, it is recommended to know what will disqualify you from donating blood first before you decide to push through this activity. Moreover, it is best to delay donating blood after critical training.

Consider giving blood during your off-season. This is when your training is simpler, and your performance is not an impending concern.

How Soon Can You Go Back To Exercising After Donating Blood?

According to the American Red Cross, it is recommended to avoid vigorous exercise or heavy lifting for at least the rest of the day after giving blood. On the other hand, the World Health Organization (WHO) recommends that a person refrains from taking part in strenuous activities or any sports for about 48 hours.

Body exercises, weightlifting, and arm-related exercises may put extra pressure on the needle site. This tends to increase the risk of bruising, bleeding, and soreness in the arm. Both anaerobic and aerobic exercises may also build up the oxygen demands of your body. If you have just donated blood, your body might not be able to keep up with those demands.

Side Effects

After giving blood, you may experience the following side effects:


It is essential to know that fatigue may occur after you donate blood. This usually happens during your body’s recovery. A person who constantly works out should not expect his body to operate at a high performance in 2 days or so directly after the blood donation.

To combat this side effect, it is recommended to get some rest. Regular and more extended breaks are a must for this one. Furthermore, working out at a minimal capacity than usual might also minimize or help prevent fatigue.


Dry mouth, dark urine, and dizziness are signs of dehydration. It is vital to know that blood donation can take away minerals and liquid from your body. It is essential to restore these liquids by consuming more than usual.

You can increase your liquid intake by drinking the following:

  • Juice
  • Broth and soup
  • Moisture-rich fruits and vegetables, such as melons, greens, and cucumbers
  • Low sugar electrolyte drinks

Iron Deficiency

Giving blood can also cause iron deficiency. As a result, less oxygen can make it into your muscles. That is why it is vital to refill these iron stores while your body recovers. The National Institutes of Health (NIH) suggests that all blood donors add foods rich in vitamin C and iron to their diet after they have donated blood.

These foods include:

  • Poultry
  • Lean meat
  • Beans
  • Tofu
  • Seafood
  • Lentils
  • Iron-fortified cereals
  • Fresh greens

In a Nutshell

Donating blood is a great way to help others in need. This process only carries little risk for fit and healthy people. However, it will help if you keep in mind that donors should limit any physical activities directly after giving blood.

As mentioned, it is recommended to wait at least a day or 48 hours before you go back to your regular training sessions. Also, you should be ready to take some regular rest periods. It is unlikely for you to be at full exercise capacity for several days. Furthermore, while in a state of recovery, it is essential to drink your water and maintain a healthy diet.

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