Ultra-Running Depletes Red Blood Cells
New studies confirm that ultra-endurance events (100+ mile runs) can significantly deplete red blood cells and accelerate their aging, potentially impacting long-term health. While ultrarunners are among the fittest athletes, their bodies pay a distinct physiological price during these extreme distances.
- The damage to red blood cells is caused by a combination of mechanical and molecular stress. The physical pounding of the feet on the ground, known as foot-strike hemolysis, directly destroys red blood cells in the capillaries of the feet. Simultaneously, the body's inflammatory response and oxidative stress contribute to molecular damage. - Research conducted on athletes running 25-mile and 106-mile races revealed that the damage to red blood cells was evident after the shorter race and significantly amplified in the longer one. This suggests that the extent of red blood cell destruction increases with the distance run. - One of the key changes observed in the red blood cells of ultrarunners is a loss of flexibility. This is significant because red blood cells need to be flexible to squeeze through tiny blood vessels to deliver oxygen throughout the body. - The accelerated aging and breakdown of red blood cells in ultrarunners mirrors the degradation process seen in stored blood for transfusions. This parallel offers a unique opportunity for scientists to study blood preservation. - The lead researcher of the study, Travis Nemkov, an associate professor at the University of Colorado Anschutz, noted that while the damage is observable, it is still unknown how long it takes the body to recover from this damage or what the long-term health impacts might be. - While intense exercise can lead to a condition known as "sports anemia," it is often due to an expanded plasma volume rather than a true deficiency in red blood cells. However, about 8% of elite athletes may develop clinical anemia.
