Analysis of over 1 million race records shows runners from East African countries as the fastest in 50-km ultra-marathons
Katja Weiss, David Valero, Elias Villiger, Mabliny Thuany, Pedro Forte, Robert Gajda, Volker Scheer, Sreten Sreckovic, Ivan Cuk, Pantelis T. Nikolaidis, Marilia Santos Andrade, Beat Knechtle
