english: Ultra-endurance was once thought to be harmful to human health, but now we realize that we have all these traits that are perfect for ultra-endurance: no body fur and a glut of sweat glands that keep us cool while running; narrow waists and long legs compared to our frames; large surface area of joints for shock absorption.
non_english: Smatralo se da je trčanje na izuzetno duge pruge štetno po zdravlje, ali smo shvatili da su nas određene osobine odlično prilagodile za to: nemamo krzno, ali imamo brojne znojne žlezde koje nas hlade dok trčimo; uzak struk i duge noge u odnosu na ostatak tela; veliku površinu zglobova koja upija potrese.