▁from ▁the ▁Kal en jin ▁eth nic ▁group ▁and ▁that ▁ 7 9 % ▁spoke ▁a ▁Nil otic ▁language . ▁ ▁Joseph ▁L . ▁Gra ves ▁arg ues ▁that ▁Ken yan ▁athlet es ▁from ▁the ▁African ▁Great ▁L akes ▁region ▁who ▁have ▁done ▁well ▁in ▁long ▁distance ▁running ▁all ▁have ▁come ▁from ▁high - alt itude ▁areas , ▁whereas ▁those ▁from ▁low - alt itude ▁areas ▁do ▁not ▁perform ▁particularly ▁well . ▁He ▁also ▁arg ues ▁that ▁Kore ans ▁and ▁E cuador ians ▁from ▁high - alt itude ▁areas ▁comp ete ▁well ▁with ▁Ken y ans ▁in ▁long - distance ▁races . ▁This ▁suggests ▁that ▁it ▁is ▁the ▁fact ▁of ▁having ▁trained ▁in ▁a ▁high ▁alt itude , ▁combined ▁with ▁possible ▁local ▁level ▁phys i ological ▁adapt ations ▁to ▁high - alt itude ▁environments ▁that ▁is ▁behind ▁the ▁success ▁in ▁long ▁distance ▁running , ▁not ▁race . ▁Since ▁Gra ves ▁wrote ▁it , ▁the ▁Nil otic ▁run ners ▁established ▁ 7 ▁world ▁records ▁in ▁mar athon ▁and ▁took ▁ 7 7 ▁Olympic ▁med als ▁in ▁running ▁( 2 5 ▁gold , ▁ 2 6 ▁silver ▁and ▁ 2 7 ▁bronze ), ▁while ▁their ▁Korean ▁and ▁E cuador ian ▁high - alt itude ▁counter parts ▁failed ▁to ▁win ▁a ▁single ▁Olympic ▁medal ▁in ▁running . ▁ ▁Gra ves ▁also ▁arg ues ▁that ▁while ▁it ▁is ▁super f icial ly ▁true ▁that ▁most ▁of ▁the ▁world ▁record hold ers ▁in ▁the ▁ 1 0 0 - met re ▁dash ▁are ▁of ▁West ▁African ▁her itage