Getting blood drawn—for tests or donation—can leave you feeling a little off. If you exercise regularly, you may be wondering how soon you can return to your routine or whether it’s safe to head to the gym right after a blood draw. This article covers common recommendations so you can decide what’s best for your health and fitness.
Table of contents:
– Is it safe to exercise right after a blood draw?
– When can you return to exercise after a blood test or donation?
– Can you work out after a fasting blood test?
– Is it safe to lift weights after a blood test?
– What about swimming after having blood taken?
– Is running OK following a blood test?
Is it safe to exercise right after a blood draw?
After a blood draw—whether for routine testing or donation—it’s best to avoid vigorous exercise immediately. Giving your body a little time to recover reduces the chance of feeling unwell.
Why avoid exercise after a blood draw?
Exercising right away can add stress to your body for a few reasons:
Physiological effects
Exercise raises your heart rate and blood pressure, which can be harder on your body if your blood volume just dropped. Strenuous activities like running or heavy lifting can make you feel light-headed or even cause fainting.
Hemoglobin and oxygen levels
When a larger amount of blood is taken—such as during donation—the effects are stronger. One study showed that exercising intensely after donating about 400 ml of blood led to lower hemoglobin, less oxygen delivery to muscles, and reduced exercise capacity for at least two days.
Puncture site healing
Activity can interfere with the needle site healing. More blood flow and movement may cause:
– Bleeding if the site reopens
– Bruising from extra pressure
Temporary symptoms
You may also experience short-term problems such as:
– Fatigue
– Dizziness or light-headedness
These symptoms can make exercise unsafe and increase the risk of falls or injury.
When can you return to exercise after a blood test or donation?
How long you should wait depends on how much blood was drawn and how you feel afterward.
Routine blood tests
Routine tests usually take only small amounts—one or two vials of about 5–10 milliliters each. If you feel fine and don’t have dizziness or weakness, you can usually do light to moderate exercise once the puncture site has stopped bleeding and is bandaged. Avoid heavy lifting or intense workouts with the arm used for the draw for the rest of the day to prevent bleeding or bruising.
Larger blood draws
If multiple vials were taken, you might feel slightly lightheaded or tired. Rest for a few hours before doing any activity and avoid strenuous exercise for the rest of the day so your body can recover.
Blood donation
Donating about 470 milliliters (one pint) removes a significant amount of blood. Groups like the American Red Cross advise avoiding vigorous exercise or heavy lifting for at least 24 hours. During that time:
– Drink plenty of fluids to help replace lost volume
– Eat iron-rich foods to support recovery
– Pay attention to symptoms like dizziness or weakness and rest if they occur
General tips
– Listen to your body: everyone reacts differently—rest if you don’t feel well.
– Stay hydrated: fluids help you recover quicker.
– Protect the puncture site: keep the bandage on for a few hours and avoid heavy use of that arm.
Can you work out after a fasting blood test?
Fasting blood tests require no food or drink (except water) for 8–12 hours before the test. You should also avoid alcohol for 24 hours before and skip exercise and heavy lifting while fasting. Fasting plus a blood draw can leave you feeling especially weak. After the test, eat a balanced meal and drink plenty of fluids before returning to activity. If you feel well, light to moderate exercise is usually fine, but avoid strenuous workouts and heavy lifting for the rest of the day, especially with the arm used for the draw.
Is it safe to lift weights after a blood test?
Heavy lifting and intense weight training are generally not recommended after a blood draw. These activities put strain on your body and could directly affect the arm where blood was taken.
Why avoid weightlifting?
– Pressure from strong muscle contractions and increased blood flow can cause bleeding, bruising, or reopening of the wound.
– Strenuous lifting temporarily raises blood pressure, which may interfere with healing.
– Overexertion can cause dizziness, nausea, or weakness—especially if you’re still recovering.
Recommendations:
– Skip heavy lifting for the rest of the day; consider waiting until the next day to resume.
– Avoid using the arm used for the draw for strenuous work.
– If you feel unwell, stop and rest; contact a healthcare professional if symptoms persist.
What about swimming after having blood taken?
Swimming—whether light laps or intense training—is usually best avoided for at least 24 hours after a blood draw. Exercise raises heart rate and blood flow, which can affect the puncture site. Hot tubs or switching between hot and cold water can also change circulation quickly and increase the risk of light-headedness or weakness. Wait a day before returning to the pool.
Is running OK following a blood test?
Running is not recommended immediately after a blood draw. It raises heart rate, blood flow, and sweating, which can increase the risk of dizziness or other uncomfortable symptoms. Avoid running right away; give yourself time to rest and recover.
The best approach after a blood test
Avoid running, heavy gym sessions, or any intense exercise right after having blood taken. Rest for about 24 hours, stay hydrated, and eat well. After that, if you feel back to normal, you can resume your regular workouts.