Is Running With Anemia Dangerous?


Physical activity has a positive impact on the body. Running helps you to maintain a healthy body and mind. Iron is the vital source of energy that provides support to red blood cells (RBC) and transports oxygen to different parts of the body. But with low iron levels, your body does not produce enough oxygen, which can deplete your energy levels and affect your running performance.

According to the statistics, 5 to 11% of men and 15 to 35% of women athletes suffer from iron deficiency. Most women athletes have low levels of iron.1 Iron deficiency causes muscle fatigue and reduces the stamina of athletes, which may be worse with running. 


Anemia is a condition in which the blood has less amount of RBC that carry hemoglobin and is unable to transfer adequate oxygen to different parts of the body. Hemoglobin is a protein that is responsible for binding with oxygen in the lungs and transferring it throughout the body. For runners, the requirement for RBC increases which means they need more iron intake.

Anemia refers to three conditions:

Low hemoglobin: The blood is unable to carry oxygen throughout the body.

Low iron: The body does not produce enough iron or it is more utilized than its intake.

Low ferritin: The body does not have enough storage of iron. Ferritin is a blood cell that is responsible for storing iron.

Anemia is the most common blood disorder. According to a WHO report, 25% of the world's population is living with this condition. Women of reproductive age, pregnant women and young children are most affected by anemia. 2,3


The causes of anemia are explained in three categories: 

  1. Blood loss 
  2. Increased destruction of RBC 
  3. Decreased production of RBC 

Blood loss:

  • Nose bleeding due to low humidity
  • Heavy blood loss due to any injury and accident
  • Heavy bleeding during menstruation or childbirth
  • Gastrointestinal bleeding in ulcer or inflammatory bowel disease
  • Any chronic condition
  • Endometriosis 

Increased destruction of RBC:

  • Autoimmune diseases
  • Certain infections
  • Chronic diseases 
  • Liver diseases
  • Side effects of medicines
  • Some inherited conditions include sickle cell anemia, thalassemia.

Decrease production of RBC:

  • An unbalanced diet lacking essential nutrients can lead to pernicious anemia due to vitamin B12 deficiency and folate deficiency anemia due to folic acid deficiency.
  • Certain infections such as tuberculosis and HIV
  • Hemolytic anemia in which the destruction of RBC occurs rapidly
  • Aplastic anemia in which the bone marrow does not produce enough RBC
  • Hormonal disorders include hyperthyroidism and hypothyroidism
  • Cancer and side effects of medication 
  • Kidney diseases
  • Genetic disorders such as thrombocytopenia, Fanconi anemia.


Symptoms of anemia depend on its cause, which can be mild to moderate and include

  • Fatigue 
  • Weakness
  • Headache or dizziness
  • Shortness of breath
  • Pale skin
  • Low aerobic capacity
  • Increased heart rate
  • Low immunity
  • Leg restless syndrome.


If anemia is not treated, it can lead to certain complications and affect different organs. 

  • Cardiac problems: Due to less oxygen, the heart pumps more blood to counteract the oxygen need, leading to increased heart rate, chest pain and heart problems.
  • Bones problem: Iron deficiency decreases bone density and develops joint pain, which further leads to osteoporosis.
  • Respiratory issues: The body needs oxygen for its function; in running, the demand for oxygen in the body increases due to increased workload, which develops difficulty in breathing and hypoxia.
  • Infection: Anemia weakens the body's immune system and makes the person, especially athletes, more susceptible to any infection.
  • Organs failure: If anemia is not treated, it may compromise normal function and affect different body organs including the liver, kidney, eye and heart.
  • Developmental issue: During pregnancy, deficiency of iron causes problems in baby growth, which increases the chances of foetal death. 4

Can running with anemia be dangerous?

Yes, running with anemia can be dangerous because runners need more iron to fulfil high work demands and with anemia, blood does not provide sufficient oxygen that helps the muscles in running. It can directly affect the performance of athletes. Runners get easily fatigued by covering small distances and with repeated long-distance running, their liver gets affected. If this condition is not treated, it may develop complications.

Can you run if you have anemia?

Yes, but if you have anemia it's better to avoid high-intensity training and long-distance running because you get easily fatigued and have shortness of breath. The body is at higher risk of developing any serious complications. However, low-intensity training does not make you feel lethargic and drains all your energy including running, swimming and simple exercise that can be done with an anemic condition.

Can Running make you anemic?

Yes, long-distance running makes your iron levels deplete faster with excessive sweating and makes you anemic. Sometimes due to muscle stiffness and hectic workout, athletes take anti-inflammatory drugs which reduce the iron absorption in the body and develop anemic condition even with the intake of an iron-rich diet.

Impacts of low iron on running performance

The deficiency of iron directly impacts the performance of runners because of an insufficient oxygen supply to the muscles.

  • Fatigue after workouts
  • Irritated by routine activities
  • Muscle stiffness
  • Body pain
  • Numbness in legs
  • Dizziness in small distance running
  • Difficulty in breathing
  • Unable to complete desired distance.

Running and high iron levels 

High iron levels are also not good for running…Yes because it develops a condition called haemochromatosis. Primary haemochromatosis is an inherited genetic change, which causes a mutation in the gene HFE, resulting in the body to absorb excess iron. Secondary haemochromatosis is due to chronic diseases, including liver disease and thalassemia, and medical treatments, thereby resulting in iron overload.5

The body absorbs iron from food but due to iron overload, the intestine can neither absorb it to reduce iron levels nor excrete it rapidly. Hence, it is absorbed in different organs mainly by the liver, causing serious health problems. In this condition, ferritin levels are high which can be used as a diagnostic indicator.

Supplementing iron

For nutritional deficiencies of iron, a balanced diet or supplements are used based on the cause of the anemia and its severity. Iron-rich food, dietary changes and iron supplements can be used after consultation with a doctor or a proper diagnosis. The doctor suggests a balanced diet between heme or non-heme iron-rich food. Food that decreases iron absorption should also be avoided.

Iron-rich foods

A natural source of food is a good way to cover iron deficiency. Iron-rich food is divided into two categories: heme iron or non-heme iron food. Heme iron found in blood and animal food is a rich source of heme iron, whereas non-heme is a plant-based food that is not easily absorbed in the body.

  • Heme iron foods: Meat, beef, chicken, poultry, eggs, tuna fish, etc
  • Non-heme iron foods: Green vegetables, lentils, beans, nuts, fruits etc

Heme-containing food contains more iron. Consumption of non-heme food with vitamin C helps in better absorption of Iron. 6


Iron supplements must be taken after your doctor's advice because iron overload is not good for the body. It is advised that iron supplements should be taken on an empty stomach. A ferrous form of iron is recommended for runners if they have an iron deficiency because it is easily absorbed in the body. Vitamin C-rich fruits or juice can be used for better absorption of iron. Avoid using any food or drink that interrupts the absorption of iron such as caffeine. 7


Running with iron deficiency affects the performance of the runner. It is the reason that can compromise the health of the runners. Iron is an essential source of oxygen, which helps to maintain the energy level of runners. The deficiency of iron can be treated with the consumption of iron-rich food and iron supplement after consulting a doctor. Add food to the diet that maximizes the absorption of iron.


  1. Sim M, Garvican-Lewis LA, Cox GR, Govus A, McKay AKA, Stellingwerff T, et al. Iron considerations for the athlete: a narrative review. Eur J Appl Physiol [Internet]. 2019 Jul 1 [cited 2022 Aug 25];119(7):1463–78.
  2. Al-Naseem A, Sallam A, Choudhury S, Thachil J. Iron deficiency without anemia: a diagnosis that matters. Clin Med (Lond) [Internet]. 2021 Mar [cited 2022 Aug 25];21(2):107–13.
  3. WHO [Internet]. [cited 2022 Aug 25].
  4. Anemia - what is anemia? | nhlbi, nih [Internet]. [cited 2022 Aug 25].
  5. Iron deficiency in runners [Internet]. Runners Connect. 2021 [cited 2022 Aug 25].
  6. Heme iron vs. Nonheme iron: what’s the difference? [Internet]. Dr. Group’s Healthy Living Articles. 2017 [cited 2022 Aug 25].
  7. Roberts WO, MD. Should all runners take iron supplements? [Internet]. Runner’s World. 2013 [cited 2022 Aug 25].
This content is purely informational and isn’t medical guidance. It shouldn’t replace professional medical counsel. Always consult your physician regarding treatment risks and benefits. See our editorial standards for more details.

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Fatima Zehra

M. Phil in Pharmacy, Hamdard University, Pakistan

Fatima is a Pharmacist and Freelance Medical Writer with working experience in Pharmaceutical,
Hospital and Community Sector. She is passionate to educate people about health care. She has a
great interest to communicate complex scientific information to general audience using her
experience and writing skill.

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