Hemolytic Anemia from Footstrikes – A Runner’s Perspective


Mechanical Hemolytic Anemia + How it Affect Runners

In 1861, an Army physician observed a soldier who had just completed arduous and demanding field marches. In his case, the soldier was suffering from foot strike anemia: one of the many names for runner’s anemia, March Hemoglobinuria. The main source of runner’s anemia is foot strike impact, which can trigger mechanical hemolytic anemia in athletes.  It is this force, according to the Journal of Applied Physiology, that initiates a cascade of events eventually resulting in bursting red blood cells. Runners are not alone, however; this condition is also commonly seen in tennis players, basketball players, weightlifters, rowers, cyclists, and ballet dancers. It has even occurred as a result of excessive hand strengthening exercises, and in people beating their head against a wall!


The rupturing process is called hemolysis: the words hemo meaning blood and lysis meaning breakdown. As the deteriorating process of hemolysis continues, the red blood cell count diminishes. This has been observed to affect overall health, performance, stamina, quality of life and sports enjoyment.  This condition is described by many names, but the methods of treatment and prevention are the same.

Mechanical Hemolytic Anemia, Also Known As:
  • Exercise-induced hemolysis
  • Exertional hemolysis
  • Foot strike anemia
  • Foot strike hemolysis
  • Hemolytic anemia
  • Intravascular hemolysis
  • Runner’s anemia
  • March hemoglobinuria (in reference to marching)
  • Mechanical hemolytic anemia
  • Microangiopathic hemolytic anemia
  • Sports anemia

In any given mile of running, your foot strikes the ground at full impact and intensity about 1600 times. The combination of continual, repetitive foot contact to the ground, the shock radiating up along your lower extremities, and anybody equipment worn as protection all play significant roles in exposure, risks, and injuries.

For more than 80 years, there are many literature reports of red blood cell hemolysis from numerous types of sports, exercise, and demanding elite activities. Most notable cases involved long-distance track runners who reported blood in their urine after racing. Exercise-induced hemolysis, specifically from long distance and marathon running, is connected to higher rates of red blood cell death.  The footstrike trauma from running is a key factor in the development of this condition.


What is Hemolytic Anemia?

Let’s start with some straightforward terms, biology, and an examination of inner working structures.  Oxygen is one component of the air we breathe, being the literal lifeblood of the human body. Whole blood is made up of several elements:

  • White blood cells (WBC) or leukocytes make up about 1% of our blood, and their lifespan is about one to three days.  They support our immune system as warriors in the first line of defense against invading infectious microorganisms. White blood cells are produced in the bone marrow at a rate of approximately 100 billion per day.
  • Plasma makes up 55% of our blood volume and consists of 92% water with additional proteins, lipids, and hormones. Plasma is the fluid transportation network; its function is to move molecules and nutrients in and out of the system. By bringing nourishment, water, hormones, medications, and proteins to your cells throughout the body, the tissues grow and behave appropriately. Plasma is also the sanitation scavenger, removing cell and tissue byproducts, waste, and discarded particles. In addition to supplying nutrition and waste elimination, plasma maintains your blood pressure.
  • Platelets make up less than 1% of our blood and have a lifespan range of nine to 12 days. They are your internal and external first aid and can be thought of as a Band-Aid produced by the bone marrow.  When we bleed, platelets circulating in the bloodstream are activated and arrive quickly at the scene. They begin the clotting process in about 12 -15 seconds to stop the bleeding. They are your plugs, and without their aid, you would never stop bleeding if you became injured.
  • Red blood cells (RBC) make-up about 44 % of our blood and have a lifespan of around 120 days. They travel from the lungs in our respiratory system to all parts of the body. Red blood cells carry oxygen and remove carbon dioxide. Every day, the average human body produces approximately 200 billion red blood cells.


Red blood cells are also called erythrocytes. The word comes from the Greek erythros meaning red and kytos meaning a hollow vessel. The primary purpose of red blood cells is to carry oxygen from the lungs in your respiratory system to every bodily organ, tissue, and cell. On the return trip, they take carbon dioxide from the cells back to the lungs, which we breathe out.

Inside red blood cells is an iron-containing protein called hemoglobin. Hemoglobin is the conveyor belt that transfers oxygen to waiting cells. When a red blood cell breaks apart, the hemoglobin goes directly into the bloodstream and reduces the quantity of oxygen available to the tissue cells for absorption.

Hemolytic anemia occurs when the rate at which red blood cells rupture and die is faster than the rate they are born from the bone marrow.  This situation can also be caused when red blood cells are removed by the spleen. This results in supply and demand becoming unbalanced, and the body fails to maintain its normal level of activity.

Recurrent traumatic impacts brought on by physical activities, such as cycling, weightlifting, rowing, biking, swimming, jogging, and long-distance movement, can cause red blood cells to rupture. If the body is able to offset the loss with its normal production of red blood cells, the cost is mild. However, in some situations the body is unable to correct itself quickly enough, resulting in low levels of hemoglobin and iron. This reduction of hemoglobin in the body is commonly referred to as anemia.


In an investigation published in the Journal of Applied Physiology, a medical team looked at the influence of running and cycling on the destruction of red blood cells. In the study, they observed 10 male triathletes. Each athlete performed two distinct sessions: one-hour of cycling and one-hour of running. These were performed one week apart at an equal peak oxygen uptake of 75%.  Doctors monitored the following substances for signs of hemolysis, comparing the two sporting activities and their outcomes:

  • Plasma or serum-free hemoglobin measures the amount of hemolysis for any given reason. Hemoglobin is found inside the red blood cells; normal plasma does not contain free floating hemoglobin levels. Its presence in the bloodstream is a common indication of red blood cell rupture.
  • Serum haptoglobin concentrations decrease as the extent of hemolytic anemia increases. Haptoglobin attaches to free plasma hemoglobin, facilitating a natural breakdown process. Low levels of haptoglobin indicate hemolysis of red blood cells.
  • Methemoglobin is a generic and general measure of trauma to the circulatory system and red blood cell stress. A high level indicates the reduction of oxygen to the tissue cells. This can eventually result in neurologic and cardiac symptoms, as the tissues become starved for oxygen.

The study results showed that both running and cycling increased plasma free hemoglobin. However, in the running component, there was a four times greater increase in plasma free hemoglobin. From cycling, there was no meaningful change in the haptoglobin levels. Despite this information, there was one important reduction after running: methemoglobin, the general substance responsible for stressor measurement, showed a twofold elevation. This happened after running and cycling, meaning that both activities reduced the oxygen supply to the tissues. There was no significant difference in the amount of methemoglobin decline between the two exercises.

Overall, the study concluded that “General circulatory trauma to the red blood cells associated with one hour of exercise… may result in some exercise-induced hemolysis,” and theorized that “footstrike is the major contributor to hemolysis during running.”

In addition, proof of exercise-induced hemolysis was found in sporting activities that do not have the presence of repetitive foot impact. This suggests the need for self-monitoring, annual blood work, and risk reduction by athletic enthusiasts involved in hard training and strenuous physical activities, as long-term performance can be affected. The term ‘pre-habilitation’ is relevant in this situation as a method to proactively mitigate or eliminate the consequences of injury and long-term harm.


Anyone can develop anemia. However, mechanical hemolytic anemia has a higher incidence in physically active people and athletes. It starts very slowly and is insidious; the signs and symptoms are so subtle that many people do not even know they have it or are at risk. The hints range from no signs or symptoms to nondescript and unspecific warnings that something is wrong, such as a general feeling of unhealthiness.

Seek out medical care if you have unexplained indications which include the following:
  • Feeling tired, worn down and fatigued
  • Faintness, dizziness, lightheaded feeling, confusion
  • Sallow, pasty, pallor skin complexion
  • Weakness, shakiness, unsteady movement
  • Reduced power and skill in a physical activity
  • Unexplained fever or infection
  • Blood in your urine or dark urine
  • Yellow shadow to the skin and whites of the eyes, similar to jaundice
  • Increased heart rate, heart murmurs, or chest pain
  • Enlarged liver and/or spleen
If these symptoms are ignored or left untreated for a long period of time, you can develop:

More information regarding potential effects of untreated runner’s anemia can be found below, under Complications.

Gastrointestinal blood loss has been detected in about 20 percent of long-distance runners. This occurs from strenuous races accompanied by traumatic mechanical kidney or renal blood loss, and these effects have not been observed in swimmers or bicyclists.

Early identification of Runner’s anemia is possible and treatable. Keep current with your yearly physical exam or doctor’s appointment. Be proactive by requesting a simple blood test, which will spot changes in the blood well in advance, especially if you are a devoted and passionate runner or athlete.



The causes of hemolytic anemia are varied and depend on age, overall health, heredity, and environmental conditions. The origin of hemolytic anemia is divided into two categories.

One is called intrinsic hemolytic anemia, meaning it comes from the inside. These are conditions in which the body itself makes defective red blood cells. The issue is innate or congenital, due to something within the organ or body.

Some examples of intrinsic causes are:
  • Genetically inherited red blood cell disorders
  • Thalassemia
  • Sickle-cell anemia
  • Paroxysmal Nocturnal Hemoglobinuria
  • G6PD deficiency of a red blood cell enzyme
  • Hereditary spherocytosis

The other category is extrinsic hemolytic anemia, coming from the external environment. These are conditions that occur from the outside of the body, where red blood cells are mechanically or biologically destroyed or damaged in the circulation. The types are usually immune or drug-related and can have other triggers.

Some examples of extrinsic causes are:
  • Auto-immune diseases such as rheumatoid arthritis, systemic lupus erythematosus, and chronic lymphocytic leukemia
  • Infectious hemolysis from gram-positive bacteria such as Streptococcus, Enterococcus, and Staphylococcus
  • Parasitic hemolysis from Plasmodium and malaria
  • Medication drug-induced hemolysis. Some examples of medicine that can induce this include acetaminophen (Tylenol), penicillin (Pen VK), ampicillin, methicillin, chlorpromazine (Thorazine), ibuprofen (Motrin), interferon alpha, procainamide, quinine, and rifampin (Rifadin)
  • Mechanical trauma destruction hemolysis
  • Prosthetic heart valve replacement surgery
  • Cardiopulmonary bypass surgery
  • Paroxysmal nocturnal hemoglobinuria (PNH), which is a very rare and life-threatening disease of the blood.
  • ABO mismatches blood transfusion reaction, where you receive the wrong type blood in a blood as a transfusion. The body’s immune system makes antibodies that quickly kill the wrong red blood cells.
  • Runner’s footstrike with worn out or inadequately cushioned shoes


Miscellaneous causes:
  • Snake or insect bites
  • Nutritional deficiencies such as Vitamin B12, Vitamin E
  • Lead poisoning
  • Burns
  • Tumors, Lymphoma
  • Myelodysplastic syndrome
  • Microangiopathic hemolytic anemia
  • Pyruvate kinase deficiency

Risk Factors

While there are many risk factors for hemolytic anemia as mentioned above, runner-specific cases of anemia have comparatively few risk factors. In addition, these can be minimized or eliminated with proactive thought and equipment. Here are some things to consider when trying to diminish the risks of developing this injury.

Risk Factors
  • Poor support from running shoes
  • Running path trail hardness
  • Overtraining with multiple consecutive training sessions
  • High intensity and frequency
  • Improper breathing
  • Faulty gait or running stride
  • Pre-existing anemia or other blood-related condition

Check the hardness of the surface you are running on. Solid, resistant, rigid pavement contributes to foot strike anemia and adds to the risk of injury with each pounding stride. Try to avoid running on hard dirt or concrete sidewalks, and instead run on grass, track, or asphalt. Wear high-quality shoes that have firm, hard insoles with soft linings and cushioning.

Establish some precautions if you are a long-distance runner, aerobic dancer, triathlete or elite athlete. This can be done by limiting the length, intensity, and frequency of your workout sessions. Lower levels of oxygen in the blood can lead to rising levels of lactic acid, resulting in acid accumulation and longer recovery times. If you continue exercising with the same frequency and disregard your extended recovery needs, the chance of injury becomes greater.

Depending on the frequency of your workouts, a single sports exercise may not lead to anemia. However, daily or twice daily incidents of hemolysis can cause iron deficiency over time. This, in turn, can affect sports activity performance and contribute to the possibility of contracting runner’s anemia, in addition to many other injuries that can be even more serious.

Read also about good running shoes for men.

Key Factors to Consider When Minimizing Risk

  • Running surface hardness and flexibility
  • Running shoes support, soft linings, hard insoles, and cushioning
  • Length and intensity of workouts
  • Recovery time before consecutive or frequent workouts
  • Annual physical exams with a doctor or medical professional



March hemoglobinuria, sports anemia, traumatic hemolysis, foot strike impacts and blood loss play an important role in differential diagnoses. There are several things your doctor or health care provider will try in order to diagnose footstrike mechanical hemolytic anemia; however, the primary diagnostic method is blood tests.

Physical Exam

Upon a physical exam, your doctor will look for a change in skin pallor and eyes. They will palpate and examine the stomach and abdominal areas. These actions will help in detecting tenderness and enlarged organs, such as your liver and spleen. This portion of the examination may also involve your doctor asking you questions about your level of activity and when you began noticing symptoms. This interview process will give your doctor more information that can be beneficial, as well as helping them form a personal action plan for you on how to treat and avoid injuries in the future.

Blood Tests

The doctor will next order an analysis of a blood sample. Within that sample there are several substances that will be checked:

  • The total amount of red blood cells. If lower than usual, this will indicate loss of blood.
  • Serum haptoglobin levels, in order to gauge the number of red blood cells in the body.
  • Reticulocytes are young, developing red blood cells. Looking at this count determine how many red blood cells your body is making, with a higher count indicating more are being manufactured to fill a need.
  • Iron and ferritin levels may be ordered to rule out iron deficiency anemia.
  • Microscopic view of the blood might be performed to confirm correct size and shape.

Additional tests may be required in order to get a full view of your condition. Some non-blood related tests a doctor may perform include:

  • urinalysis will look for blood in the urine, especially within hours of days or of exercise.
  • Liver function tests will check the overall health of your liver. The accompanying bilirubin will measure the number of red blood cells the liver has broken down.
  • Rarely is a bone marrow aspiration or biopsy completed? This provides information as to how many red blood cells are being made and what their shape is.
Erythropoietin (EPO) Oxygen Doping

In some sports sectors, there is the extensive and well-known use of erythropoietin (EPO) doping among athletes and competitors. A recent high-profile example of an athlete doping in this way is Lance Armstrong, who wound up losing his Tour de France victories when caught doing this. Erythropoietin is a natural hormonal protein our bodies release from the kidneys. This hormone activates bone marrow to make more red blood cells, which can then bring more oxygen to tissues, organs, and cells.

The prescription medication of erythropoietin is called epoetin alfa (Epogen or Procrit). It is given as an injection into a vein or under the skin. Epoetin alfa is approved for use in people who have kidney disease and require dialysis. The agent treats and prevents chronic renal failure anemia by artificially increasing red blood cell production.

Blood erythropoietin doping is hard to detect. A red flag possibly indicating misuse is a high hematocrit level, as revealed by a blood test. Exercise, training, and working out would ordinarily cause the hematocrit to be lower. Everything has side effects and risks, but many of the risks from EPO are unknown and will not be knowable until sometime in the future. The bottom line when it comes to blood doping is sticking to your personal ethics, following the rules of your sport of choice, and maintaining your health now and in the long-term.



Unless intense, frequent, and severe over a long period of time, footstrike hemolysis will not negatively affect your health. Treatments differ based on the cause and severity of hemolysis as well as your age, health, and tolerance to medications.

Mild cases will resolve on their own with time, rest, and recovery. For most runners and athletes, the reduction of physical activities is the most difficult aspect of the recovery process. However, it is very important to take some well-deserved time off, and perhaps even try another sport or physical activity. If you are in a position where this isn’t an option. For example, if you are a long distance running athlete training for a major event, here is a method you may wish to consider. While it is recommended that a rest period is taken from intense exercise, some people prefer to start cross-training in these cases. An example of this is performing cardiovascular exercises that put less stress on your feet, such as cycling or swimming. This is also a terrific opportunity to try another sport. Either way, cases of runner’s anemia are cured most easily and quickly with rest, recovery, and treatment.

The Athlete's Guide to Recovery: Rest, Relax, and Restore for Peak Performance

Changes in diet or prescription medication are often not necessary. In rare but critical conditions, a blood transfusion may be needed. This method will quickly increase red blood cells and oxygen supply via direct replacement. In the most serious cases where the spleen is found to be destroying red blood cells, surgery may be required to remove the spleen.

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All medications have risks, benefits, and side effects. Consult your healthcare provider before starting anything new.

Some medications used in the treatment of severe conditions include:
  • Immunoglobulin: In cases where hemolytic anemia is caused by an immune system deficiency, one potential treatment method is an intravenous immunoglobulin. This medication is derived from plasma in the human body, and the role that it plays in treatment is to enhance the function of the immune system, which can prevent some cases of anemia.
  • Corticosteroids: These are synthetic versions of steroids that otherwise occur naturally in the body, and are responsible for muscle and tissue growth. Treatment with this kind of medication can be very useful since it can bolster the immune system, as well as block the body from making antibodies that destroy red blood cells.
  • Folic acid: Some cases of anemia are caused by a lack of folate or folic acid. In these cases, a medicine containing folic acid can be used to treat this injury. This form of treatment is common among pregnant women, as they are the most prone to folate-deficiency anemia. Folic acid can also be supplemented through a diet high in leafy green vegetables and animal liver.
  • Cancer medicine: A few different forms of medication used to treat different types of cancer can be effective in treating hemolytic anemia as well. One example of this is hydroxyurea, a medicine used for treating leukemia, ovarian cancer, and skin cancer. One effect this drug has on the body is that it increases the production of fetal hemoglobin, which can be highly effective at combating sickle cell anemia. Another common cancer drug treatment is Rituximab, a chemotherapy medication that can bolster the immune system. This effect makes it an excellent treatment method for immunodeficiency related cases of anemia, as a scientific study has confirmed.

A non-drug way to limit, prevent, and treat this condition is to look at your shoes! You have invested a lot of time, sweat, coaching, training, and devotion to your chosen sport. Great footwear combined with insole hardness reduces impact forces, which can go a long way toward preventing a variety of running injuries on top of hemolytic anemia. Studies have repeatedly shown that adjusting the hardness of shoe insoles is a successful technique for reducing the amount of hemolysis. Harder insoles are more effective at preventing this injury when compared to soft insoles.


See them here: (Insoles for FootStrikes)

Red blood cells require iron to perform optimally. Every day we lose one to two milligrams of iron as a normal bodily process. This amount is easily absorbed from the small intestine and replaced by the foods we eat. However, in some instances, your health care provider may recommend an iron sulfate or iron gluconate replacement vitamin. These can be purchased without a prescription; check with your doctor for your individualized dosing and length of therapy. Oral iron supplements can potentially cause gastrointestinal issues, constipation, nausea, vomiting, abdominal discomfort, and dark tarry looking stools. Blood tests will also need to be performed after some time of supplementation, in order to ensure your body’s iron and ferritin levels have returned to their normal ranges.

Iron loss in sports activities and exercise is cumulative. This can occur in athletes who partake in other forms of physical training: tennis and basketball players, weightlifters, cyclists, and ballet dancers. It is mainly derived from the number of consecutive training sessions, frequency and intensity of hemolysis cases, perspiration, gastrointestinal bleeding, and hematuria (blood in the urine).

When the condition of iron deficiency anemia is diagnosed, your doctor will prescribe the appropriate type and dose of iron replacement therapy for you. The incidence of iron deficiency anemia increases in people who follow a vegetarian diet, young-adolescent, and females who are menstruating.

While iron does have a relevant function in an athlete’s performance, do not start any iron supplementation without seeking medical advice from a healthcare provider. Taking too much iron can harm the heart and liver, and may result in a condition called hemochromatosis.

Summary Checklist of What to Expect in Treatment:
  1. One or more appointments with a doctor or healthcare professional.
  2. Physical exam
  3. Blood work
  4. Urine and stool tests
  5. Possible medications (iron supplement, immunoglobulin, corticosteroids)
  6. Additional sports equipment (firmer insoles, softer lining, and supportive structure)
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According to the Journal of Sports Medicine, Arthroscopy, Rehabilitation, Therapy and Technology, firmer insoles successfully reduce cases of hemolysis in runners.  Shock absorbing insoles limit the intensity and frequency of impact forces caused by foot strikes. Therefore, this simple change in footwear is a highly effective method of preventing runner’s anemia, in addition to the selection of soft running paths and running shoes with extra cushion.

Example of a highly cushioned, well-supported shoe


See more here: (Highly Cushioned Running Shoes)

A study compared soft and firm insoles on the development of runner’s hemolysis. In the group of athletes using soft insoles with less cushioning, there was a significant increase in cases of hemolysis. The conclusion reached by this study was that the softer the insoles were, the higher the rate of red blood cell rupture was. Conversely, the group that used harder insoles showed less hemolysis, as the equipment successfully limited the intensity of repetitive foot impact.

Here are some proactive preventative measures you can take to minimize any risk or cumulative harm:
  • Replace your running shoes consistently. It is not in your best interest to completely wear out your running shoes before investing in another good pair. A constant level of shock absorption and adequate firmness is necessary when exercising. It may seem beneficial financially to completely wear out one pair of shoes before moving on, but this will drastically increase your chances of injury.
  • Wear hard, firm insoles. The shoes you wear should have shock absorbing capabilities and soft inner linings. This will lessen and limit the impact forces that radiate up the lower extremities with each step you take. It is important to realize that even with better-designed footwear containing padded or firmer insoles, there will still be some hemolysis, just from the pressures of walking and running.
  • Locate and run on softer surfaces. Do this as much as possible, because the overall texture of the terrain you run on will augment the level of impact your feet and lower body sustain. As a general rule, Olympic-style track and grass are the ideal running surfaces. Alternatively, hard dirt, concrete, and asphalt are surfaces you should avoid running on whenever possible.
  • Analyze and correct your posture and gait. Consider having your gait analyzed by a physical therapist at a gait analysis clinic. Any discrepancies in your running technique can increase the possibility of sustaining many injuries, not just hemolytic anemia. Runners who were encouraged to modify their gait and running technique ultimately found themselves with a reduced level of hemolysis.


Some dietary changes you can make to help prevent this condition include:
  • Incorporating more iron into your diet: Anemia can be caused by a lack of iron; additionally, when it occurs in your body, even more, iron is lost and the problem is worsened. For these reasons, it is important to add foods rich in iron to your diets, such as various meats and vegetables. Turkey, chicken, pork, and liver are high in heme iron, a form of iron that is more easily absorbed into your body. Non-heme iron can be found in spinach, broccoli, kale, and lentils, and while they may be more difficult for your body to absorb, they still play a very important part in a balanced diet. If you can’t add more iron-rich foods to your diet for whatever reason, this can also be accomplished through the use of supplements such as iron pills.
  • Incorporating more folic acid into your diet: Folic acid deficiency can lead to anemia in some cases. This is more prevalent in pregnant women, which is why doctors will often recommend that they take folic acid supplements during their pregnancy. This is absolutely a good idea for pregnant women, but for others, it is sufficient to simply add some foods that contain folic acid into their diet. The FDA requires manufacturers of certain grain products, such as cereal and rice, to add folic acid to their foods. This can make for a decent addition to the diet of an American, but for individuals in other countries, they will need to find it elsewhere. Other foods high in folic acid include spinach, Brussels sprouts, avocado, and asparagus.
  • Replacing simple carbohydrates with complex carbohydrates: Carbohydrates play an important role in energy production for the body, as they are broken down into glucose which provides the body with energy. Depending on what form they come in, however, the benefits can be outweighed by the potential negative side effects. Consuming too many simple carbohydrates will raise your blood’s glucose levels very quickly, which can lead to many circulatory problems such as type 2 diabetes and obesity. These conditions make it much more difficult to treat runner’s anemia, and obesity, in particular, can increase your risk of developing the condition, as foot strike impact is much worse the more you weigh. Instead, try eating foods with more complex carbohydrates, such as whole grains and starchy vegetables like sweet potatoes and squash. This will provide your body with the glucose it needs, while also providing other valuable substances such as fiber.
  • Reducing cholesterol consumption: A diet too high in cholesterol can cause many issues in your circulatory systems, such as high blood pressure and the possibility of clots and thrombosis. Additionally, cholesterol-rich foods are a major contributor to obesity. These effects of high cholesterol on the body make hemolytic anemia much more likely to occur and much more difficult to treat. For these reasons, it is a good idea to cut foods high in cholesterol out of your diets, such as butter, bacon, fries and potato chips. You may also need to take special medication that reduces high blood cholesterol if this is a major health concern.

False Positives

There may be a situation where you believe that you have one injury when in actuality you are suffering from a completely different one. A test result that shows a condition that does not exist is called a false positive. A false positive is an error and mistaken result; in the case where you are diagnosed improperly, this is also considered a false positive. It is important when undergoing a medical diagnosis that multiple and varied parameters are tested and verified by a medical professional. Experienced clinicians and laboratories will run multiple different tests, and will double check the accuracy of their results. However, mistakes can happen, and there are several potential ailments that can result in a false diagnosis when being screened.

They include:
  • Toxins: The presence of toxins in the body can contribute to feelings similar to symptoms of runner’s anemia. If you experience fatigue, shortness of breath, dizziness, or trouble recovering from a workout, this can be a potential culprit. Some toxins that can cause these issues if they are concentrated in the body include arsenic, metals, copper, nickel, lead, chromium/chromates, and platinum. You can avoid exposing your body to these chemicals by filtering your water and avoiding drinking out of plastic bottles.
  • Muscle StrainIf you feel fatigued more easily after a workout, and you notice weakness in your extremities, another potential culprit is a muscle strain. In the case of muscle strain, your symptoms are not caused by a failure of your circulatory system, but by overworking a specific body part. During a physical examination and interview, a doctor or healthcare provider can help you determine if this is the cause of your condition.
  • Hepatitis: A viral infection of the Hepatitis virus carries many similar symptoms to hemolytic anemia. This includes nausea, fatigue, and a fever. However, this condition can be differentiated due to its other symptoms, such as jaundice in the eyes or skin and belly pain. Blood tests are the best way to rule out this condition when receiving a diagnosis.
  • Systemic Lupus Erythematosus: More common in women, this is an autoimmune disease where your body’s immune system begins attacking itself mistakenly. Some symptoms it shares with foot strike anemia include fever, general discomfort, fatigue, heart problems, and nausea. The way that SLE is different from anemia is that it can also affect the skin in the form of rashes, and the brain in the form of vision problems and seizures. X-rays and urinalysis are used in a medical diagnosis to detect this condition.
  • Epstein-Barr virus: This is a very common form of herpes that many individuals contract at some point in their lives. It is the cause of mononucleosis, also referred to as mono. This condition shares the symptoms of fatigue and fever, but it also exhibits different symptoms in the form of rashes and swollen lymph nodes. Detecting this condition can be tricky, as it can imitate a variety of other injuries and illnesses, but a blood test analyzing your antibodies is effective at ruling this out during a diagnosis.
  • Typhoid fever: This condition is very rare in the developed world, with cases generally contained to third world countries. It is caused by exposure to infected individuals, or through contaminated food and water. High fever, headaches, muscle fatigue, and nausea will be some common observable symptoms, but some different symptoms of Typhoid fever include constipation, rashes, and a swollen abdomen. Antibodies and vaccines are used to treat this condition. Your doctor will diagnose this condition by asking you about recent travel habits, and by taking a sample of your blood, urine or stool to check for bacteria.
  • ArthritisFatigue, higher than normal body temperature, fevers, and limited mobility are some symptoms this condition shares with hemolytic anemia. However, arthritis is a vastly different condition, with fundamentally different causes and methods of treatment. One way to differentiate arthritis from anemia is to locate the specific points of weakness, as arthritis is most commonly felt in the joints.
  • Sickle cell anemia: Also known as Sickle Cell Disease, this is a hereditary condition, meaning it is passed on genetically as a mutation. Those affected by this condition have fundamentally different red blood cells than those who aren’t affected; their blood cells take a thin, sickle-like form as opposed to the standard doughnut shape. These differently shaped red blood cells have a tougher time carrying oxygen to the organs in your body, and also have a higher likelihood of clogging in your arteries. This is a lifelong condition, but there are steps doctors can take to mitigate symptoms, and a cure is currently in development.
  • Cancer: Leukemia, lymphoma, and other forms of tumorous growth can exhibit symptoms identical to those relating to hemolysis. Some common symptoms include fatigue, muscle weakness, shortness of breath and headaches. Some symptoms that leukemia and lymphoma do not share with anemia include swollen lymph nodes, recurring nosebleeds, and small red dots on the skin (petechiae). Fortunately, most forms of cancer can be detected fairly easily with a proper medical diagnosis, so any confusion between the two injuries is easily resolved. Unfortunately, cases of cancer are much harder to treat, and can be potentially life-threatening.
  • Medicine: There is always the potential for side effects or complications from medication causing a false positive for this condition. Penicillin, pain medication, Dapsone, quinine, nitrites, and nitrofurantoin exhibit side effects that can confuse some individuals into believing they are experiencing runner’s anemia. This is why a good doctor or health care provider will ask for your history of medicine use; this way, they can rule out side effects from errant medication as a potential cause.
  • Streptococcus infection: Some forms of streptococcus infection can exhibit symptoms that are shared with hemolytic anemia, such as shortness of breath, high fever, and irregular heart rhythms. This bacteria is contagious and can lead to such illnesses as strep throat and pneumonia. For these reasons, it is very important to obtain an accurate diagnosis from your health care provider and begin antibiotic treatment as soon as possible in order to prevent more serious complications.
  • Wiskott-Aldrich syndrome: This is a rare immunodeficiency that affects the platelets in your blood. It is hereditary and causes a mutation in the blood platelets, similar to sickle cell anemia. The platelets take a much smaller form, causing the body to become much more prone to bleeding. High fevers and difficulty with blood circulation are some shared symptoms, but Wiskott-Aldrich syndrome also causes eczema to develop and can lead to much more debilitating complications, such as sepsis, meningitis, or leukemia.
One must also take into account the following when diagnosing hemolytic anemia:
  • Blood in the urine, (hematuria)
  • Low iron in the red blood cells
  • Preexisting medical disorders
  • Family medical history
  • Prior running injuries


As previously mentioned, runner’s anemia isn’t the end of the world if it occurs every so once in a while. The standard course of action when dealing with this injury is to treat it as a warning sign: a bit like the ‘check engine’ light in your car. It’s a signal your body is sending to you that means something you are doing is causing problems with your overall health, and you need to change things up. If you disregard this warning and continue the same routine that caused your foot strike anemia in the first place, it is possible that your condition will worsen and complications will develop. Be sure to identify and treat this injury promptly in order to avoid the following complications:

  • Loss of strength: One effect this injury has on your body is that it prevents your muscles from operating at their full capacity. Since your body loses the ability to provide adequate amounts of oxygen to your organs and tissues, this will result in a loss of physical ability. As a result, you may notice that you are unable to run for as long or as fast as you used to. If you lift weights, you may notice that you can’t lift as heavy of weight for as long as you used to. Over time, training at a reduced capacity like this will cause the body to change, resulting in a permanent loss of your prior ability.
  • Gallstones: Over time, decreased iron as a result of chronic cases of anemia will cause an excess production of bilirubin, a substance that is normally produced as a part of bile. This surplus results in the substance building up in the biliary tract, which will eventually lead back to your gallbladder. Once it reaches the gallbladder, the substance crystallizes and forms cholelithiasis or gallstones. Scientific studies have proven the link between anemia and gallstones,  and the negative effects this condition can have includes abdominal pain and potential liver damage.
  • Jaundice: Another effect that the buildup of bilirubin can have on your body is that it begins entering into your bloodstream. This can occur in conjunction will gallstones, as the main cause of this condition is complications of the gallbladder. Once bile enters your bloodstream, your fluids begin to turn yellow, and your skin and eyes will begin displaying a yellow tint as well. Vomiting, fever, abdominal pain and significant weight loss are symptoms of this condition, with some cases becoming so severe and painful that some of those afflicted have been drawn to suicide!
  • Thromboembolism: Hypercoagulation, or excessive blood clotting, has occurred in many individuals affected by anemia. The effect this has on the circulatory system is that clogs can occur in your arteries, causing a condition known as deep vein thrombosis.  Over time, clogs such as these can become detached from their point of origin and travel up your veins toward the heart, eventually causing a pulmonary embolism.



The literature supports the statement that red blood cell hemolysis happens from many different sports, exercises, and physical activities.

The condition accepted as foot strike mechanical hemolysis, or exertional hemolysis, is caused by repeated trauma to the soles of the feet upon hitting the pavement. Associated with the destruction of red blood cells, the sustained chronic impact from repetitive movement has shown influences on red blood cell loss, iron deficiency anemia, and hematuria.

A runner or athlete’s iron deficiency stage can keep them from optimizing aerobic strength and dampen their overall performance.

There are important health issues that accompany iron deficiency and iron deficiency anemia, in both males and females. With monitoring,  treatment, and several follow-up visits, proactive measures can be taken. By selecting adequate insoles, cushioned shoes, competitors, and trainers, red blood cell hemolysis can be lessened and possibly negated entirely.

The most important thing you need when training for any sport is a devotion: train hard, use the best equipment and maintain balance with healthy dietary choices and supplements.

If you find yourself beginning to have to work harder and make more of an effort than before, it may be time for a physical check-up. Unexplained tiredness, fatigue and sleeping difficulties are not the norm, and your body may, in fact, be sending you the message that something is wrong. In the words of the legendary Bruce Lee, “There are no limits. There are only plateaus, and you must not stay there, you must go beyond them.” If you find yourself reaching a plateau, you may need to consult a doctor in order to go beyond.

Trace elements in the blood, such as iron, keep your body functioning at its peak performance level.

Iron, as well as many other vital nutrients, is responsible for maintaining your immune system and energy production structures. Your entire circulatory system is burdened with sustaining your body; carrying oxygen to starved tissues is a huge task on its own, but it becomes even more difficult when your exercise workload is large and intense. Muscles, ligaments, brain, and heart all need oxygen while you are running, and it takes all of them working at their full capacity in order to complete a marathon.

Staying healthy means listening to your body.

It means taking the time to make appointments and follow up on them with physical exams, blood and urine tests, and possible visits to the pharmacy. It also means keeping your equipment up-to-date, stable, supportive, and not in tatters!

When it comes to running, physical activity, and sports, the season is always right, no matter what time of year.

Be proactive: seek information and knowledge covering all aspects of your sport. When taking the initiative to be safe and curtail injuries, you will continue to enjoy this sport you love, the camaraderie from fellow teammates and enthusiasts, and thrive when making progress and smashing personal records.

Co-written by Mike Valverde

Curated by Diana Rangaves, PharmD, Rph


This material contained in this article is not intended as a substitute for medical recommendations. It is supplied by RunnerClick as a guide to initiate questions and discussion with your healthcare provider. Make sure you discuss any questions you have with a doctor or medical professional, as related to your unique conditions and concerns. This article was researched using sound, credible references, listed below for your further investigations.


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