Five of the all-time greats still hold records in their respective events:
Florence Griffith Joyner (100, 200)
Marita Koch (400)
Jarmila Kratochvílová (800)
Junxia Wang (3000)
Jackie Joyner-Kersee (heptathlon)
Why have their records persisted for so long? What do these five supreme athletes have in common that makes it so difficult for modern-era athletes to break their records?