Pushing the body to ultra-marathon distances may cause red blood cells to become less flexible, potentially hindering their ability to deliver oxygen and remove waste. A new international study suggests the extreme stress of these runs may exceed the body's recovery capabilities, leading to damage in these vital cells.
Researchers analyzed blood samples from elite runners in races of approximately 25 miles and 106 miles. They found signs of mechanical and molecular damage to red blood cells, consistent with accelerated aging and breakdown. This wear and tear was notably greater in the ultra-marathon runners.
Specifically, red blood cells became less flexible, potentially leading to their premature removal from circulation. Additionally, a key red blood cell repair mechanism appeared to be overwhelmed. While the study observed this damage, long-term health implications remain unknown. Researchers noted the damage observed is similar to that seen when blood is stored for transfusions, suggesting potential avenues for improving blood storage techniques.