Running extreme distances may strain more than just muscles and joints. New research suggests ultramarathons can alter red blood cells in ways that make them less flexible and more prone to breakdown, ...

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

Researchers collected blood from 23 runners right before and right after two endurance races: a 40-kilometre mountain race ...

Ultramarathons might push red blood cells past their limits—accelerating their aging in the process.

Red blood cells normally cannot move on their own; they lack any of the cell structures needed for movement. Instead, they deliver oxygen throughout the body by going with the flow of blood. So, when ...

Behavior of a spherical capsule in a pulsatile flow. A single capsule moving in the direction of the flow is superimposed. Fukuoka, Japan—As you read this sentence, trillions of cells are moving ...