Why Do We Taste Blood After A Long Run?

Have you ever experienced a metallic taste in your mouth after a long run or an intense workout? Many runners report tasting blood, and while it can be unsettling, it’s usually not a cause for concern. Understanding why this happens can help you avoid unnecessary worry and take the necessary steps to prevent it. 

To better understand the same, our team at OnlyMyHealth connected with an expert, Dr Malla Devi Vinaya, General Physician, MBBS, MD, Apollo Clinic Kondapur.

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What Causes You To Taste Blood?

The taste of blood after a long run is typically linked to the body’s response to intense physical exertion. When you push yourself during a run, your body undergoes various physical changes, especially in the respiratory system. One of the common causes for the metallic or “bloody” taste is due to tiny blood vessels in the lungs or respiratory tract breaking under the strain.

The tiny blood vessels in the lungs, known as capillaries, are fragile. When you run for long periods or at high intensity, the increased air intake and pressure in the lungs can cause these vessels to rupture. This is often the main reason why some runners report tasting blood. Fortunately, these ruptures are typically minor and usually heal quickly without causing long-term damage.

It’s during these situations that the heart works harder than it’s conditioned to work, thus leading to a buildup of fluid in the lungs known as pulmonary edema. When this fluid builds up, the increased pressure leads to leakage of red blood cells into the small air sacs of the lungs and a release of haemoglobin from the red blood cells. Haemoglobin is a molecule contained in red blood cells that is key for allowing them to transport oxygen. Haemoglobin molecules are bound to a central ion of iron, which is why you get a metallic aftertaste.

Is It A Cause For Concern, Diagnostic Tests To Ascertain

For most healthy individuals with good oral hygiene, experiencing a metallic taste while running is more unpleasant than concerning, you needn't worry about it. However, there are instances where this sensation may indicate the need for medical evaluation.

Dr. Vinaya suggests taking the following diagnostic tests to ascertain the actual cause and determine whether it is serious or can be ignored. This will enable you to opt for appropriate treatment options. 

Muscle Inflammation/Micro Injury

Any forms of muscle tears or damage can be checked through raised creatine phosphokinase (CPK) and myoglobin in blood.

Medical Monitoring

Intense physical activities can cause severe dehydration ,so performing blood tests post exercise can help us determine any electrolyte imbalances like sodium chloride, potassium and magnesium abnormalities.

Renal Assessment

Kidney functioning needs to be assessed to know the effect of strenuous exercise on kidneys.

Serial Monitoring Of Blood Tests After Exercise

This can help in training and performance of the athletes and also helps to know their physiological responses to exercise and accordingly training programs can be optimised. This helps in reducing the risk of illness and injuries.

Blood Tests

These tests can be used to assess the nutritional status of athletes which guides especially during recovery period.

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How to Prevent or Minimise the Metallic Taste?

Although you can’t always avoid the minor blood vessel ruptures that cause a metallic taste during exercise, several steps can help reduce its occurrence:

Maintain Proper Hydration

Drinking enough water before, during, and after your run can prevent dehydration, which often worsens throat irritation and dryness.

Start Slowly 

Gradual warm-ups help ease your body into activity and reduce unnecessary strain on your lungs and airways.

Know Your Limits

Avoid pushing yourself too hard, especially if you’re new to running or increasing your workout intensity. 

Master Your Breathing

Practising deep, steady breathing during exercise can decrease stress on your respiratory system, making workouts more comfortable.

If you notice a metallic taste regularly or experience symptoms like coughing up blood, dizziness, or chest pain, it’s important to consult a medical professional. These could indicate an underlying condition that needs evaluation.

What Your Body Is Telling You During Intense Exercise?

Tasting blood after a long run is usually a harmless response to intense physical exertion. It occurs due to small capillaries in the lungs or respiratory tract rupturing under pressure, causing blood to enter the airways and produce that metallic taste. By understanding the causes and taking simple preventive measures like staying hydrated and warming up properly, you can reduce the likelihood of this happening. However, if the sensation persists or is accompanied by concerning symptoms, it’s always a good idea to check in with your doctor to rule out any underlying health issues.