After a long trail race, some of your red blood cells may not bend the way they should. That matters because red blood cells have a tight job description.

Running extreme distances may strain more than just muscles and joints. New research suggests ultramarathons can alter red ...

By Dennis Thompson HealthDay ReporterTHURSDAY, Feb. 19, 2026 (HealthDay News) — Ultra-marathon runners must be incredibly fit to endure races that can extend more than 100 miles, but their bodies pay ...

Learn more about the impact ultramarathon running has on red blood cells and how it may do more harm than good for the body.

Running is good for your health, but pushing it too far can take a hidden toll. New research shows that ultramarathons may damage red blood cells, making them less flexible and potentially speeding up ...

Researchers collected blood from 23 runners right before and right after two endurance races: a 40-kilometre mountain race and the 171-kilometre Ultra Trail du Mont Blanc. They then analyzed thousands ...

Extreme endurance running damages red blood cells in ways that may affect their ability to function properly, according to a ...

A study published 19 February in Cell Metabolism, a Cell Press journal, found red blood cells step in as a major 'glucose ...