Athletics - Berlin Marathon - Berlin, Germany - September 16, 2018 Kenya's Gladys Cherono Kiprono (C) poses after winning the Berlin Marathon alongside second placed Ruti Aga (L) of Ethiopia and third placed Tirunesh Dibaba also of Ethopia (R) REUTERS/Fabrizio Bensch

Athletics - Berlin Marathon - Berlin, Germany - September 16, 2018 Kenya's Gladys Cherono Kiprono (C) poses with her medal after winning the Berlin Marathon alongside second placed Ruti Aga (L) of Ethiopia and third placed Tirunesh Dibaba also of Ethopia (R) REUTERS/Fabrizio Bensch

Ethiopian athlete Tirunesh Dibaba holds an Eritrean flag during a welcoming ceremony of Eritrean Foreign Minister Osman Saleh and his delegation at the Bole International Airport in Addis Ababa, Ethiopia June 26, 2018. REUTERS/Tiksa Negeri

Athletics - London Marathon - London, Britain - April 22, 2018 Ethiopa's Tirunesh Dibaba takes a drink during the women's elite race REUTERS/Peter Cziborra

Athletics - London Marathon - London, Britain - April 22, 2018 Ethiopa's Tirunesh Dibaba takes a drink during the women's elite race REUTERS/Peter Cziborra

Athletics - World Athletics Championships – women’s 10,000 metres victory ceremony – London Stadium, London, Britain – August 6, 2017 – Tirunesh Dibaba of Ethiopia (Silver), Almaz Ayana of Ethiopia (Gold) and Agnes Jebet Tirop of Kenya (Bronze) pose with medals.

Athletics - World Athletics Championships – women’s 10,000 metres victory ceremony – London Stadium, London, Britain – August 6, 2017 – Tirunesh Dibaba of Ethiopia (Silver), Almaz Ayana of Ethiopia (Gold) and Agnes Jebet Tirop of Kenya (Bronze) pose with medals. REUTERS/Phil Noble

Athletics - World Athletics Championships – women’s 10,000 metres victory ceremony – London Stadium, London, Britain – August 6, 2017 – Tirunesh Dibaba of Ethiopia (Silver), Almaz Ayana of Ethiopia (Gold) and Agnes Jebet Tirop of Kenya (Bronze) pose with medals. REUTERS/Phil Noble

Athletics - World Athletics Championships - Women's 10000 Metres Final - London Stadium, London, Britain – August 5, 2017. Almaz Ayana of Ethiopia celebrates winning the final with Tirunesh Dibaba and Dera Dida. REUTERS/Kai Pfaffenbach

Athletics - World Athletics Championships - Women's 10000 Metres Final - London Stadium, London, Britain – August 5, 2017. Tirunesh Dibaba of Ethiopia celebrates after the final.

Athletics - World Athletics Championships – women’s 10000 metres final – London Stadium, London, Britain – August 5, 2017 – Dera Dida, Almaz Ayana and Tirunesh Dibaba of Ethiopia celebrate after the race. REUTERS/Kai Pfaffenbach

Athletics - World Athletics Championships – women’s 10000 metres final – London Stadium, London, Britain – August 5, 2017 – Almaz Ayana and Tirunesh Dibaba of Ethiopia celebrate after winning gold and silver medals. REUTERS/Kai Pfaffenbach

Athletics - World Athletics Championships – women’s 10000 metres final – London Stadium, London, Britain – August 5, 2017 – Tirunesh Dibaba of Ethiopia and Agnes Jebet Tirop of Kenya finish the race. REUTERS/Phil Noble

Athletics - World Athletics Championships – women’s 10,000 metres final – London Stadium, London, Britain – August 5, 2017 – Almaz Ayana of Ethiopia and Tirunesh Dibaba of Ethiopia react. REUTERS/Lucy Nicholson

Athletics - World Athletics Championships – women’s 10,000 metres final – London Stadium, London, Britain – August 5, 2017 – Tirunesh Dibaba of Ethiopia competes. REUTERS/Lucy Nicholson

Britain Athletics - London Marathon - London - 23/4/17 Kenya's Mary Jepkosgei Keitany poses with the trophy as she celebrates winning the Women's Elite race with second placed Ethiopia's Tirunesh Dibaba and third placed Aselefech Mergia Medessa Action Images via Reuters / Matthew Childs Livepic

Britain Athletics - London Marathon - London - 23/4/17 Kenya's Mary Jepkosgei Keitany poses as she celebrates winning the Women's Elite race with second placed Ethiopia's Tirunesh Dibaba and third placed Aselefech Mergia Medessa Action Images via Reuters / Matthew Childs Livepic

Britain Athletics - London Marathon Previews - London - 19/4/17 (L-R) Mare Dibaba, Tigist Tufa, Mary Keitany, Vivian Cheruiyot and Tirunesh Dibaba ahead of the 2017 Virgin Money London Marathon Action Images via Reuters / Matthew Childs Livepic

Britain Athletics - London Marathon Previews - London - 19/4/17 (L-R) Tirunesh Dibaba, Tigist Tufa, Mare Dibaba of Ethiopia and Florence Kiplagat, Mary Keitany and Vivian Cheruiyot of Kenya ahead of the 2017 Virgin Money London Marathon Action Images via Reuters / Matthew Childs Livepic

Britain Athletics - London Marathon Previews - London - 19/4/17 (L-R) Tirunesh Dibaba, Tigist Tufa, Mare Dibaba of Ethiopia and Florence Kiplagat, Mary Keitany and Vivian Cheruiyot of Kenya ahead of the 2017 Virgin Money London Marathon Action Images via Reuters / Matthew Childs Livepic

Britain Athletics - London Marathon Previews - London - 19/4/17 (L-R) Tirunesh Dibaba, Tigist Tufa, Mare Dibaba of Ethiopia and Florence Kiplagat, Mary Keitany and Vivian Cheruiyot of Kenya ahead of the 2017 Virgin Money London Marathon Action Images via Reuters / Matthew Childs Livepic

Britain Athletics - London Marathon Previews - London - 19/4/17 (L-R) Tirunesh Dibaba, Tigist Tufa, Mare Dibaba of Ethiopia and Florence Kiplagat, Mary Keitany and Vivian Cheruiyot of Kenya pose for a photo in front of Tower Bridge ahead of the 2017 Virgin Money London Marathon Action Images via Reuters / Matthew Childs Livepic

Britain Athletics - London Marathon Previews - London - 19/4/17 (L-R) Tigist Tufa, Tirunesh Dibaba and Mare Dibaba of Ethiopia ahead of the 2017 Virgin Money London Marathon Action Images via Reuters / Matthew Childs Livepic

Britain Athletics - London Marathon Previews - London - 19/4/17 (L-R) Tigist Tufa, Tirunesh Dibaba and Mare Dibaba of Ethiopia pose for a photo in front of Tower Bridge ahead of the 2017 Virgin Money London Marathon Action Images via Reuters / Matthew Childs Livepic

2016 Rio Olympics - Athletics - Final - Women's 10,000m Final - Olympic Stadium - Rio de Janeiro, Brazil - 12/08/2016. Almaz Ayana (ETH) of Ethiopia celebrates next to Tirunesh Dibaba (ETH) of Ethiopia. REUTERS/Alessandro Bianchi FOR EDITORIAL USE ONLY. NOT FOR SALE FOR MARKETING OR ADVERTISING CAMPAIGNS.
Picture Supplied by Action Images

2016 Rio Olympics - Athletics - Final - Women's 10,000m Final - Olympic Stadium - Rio de Janeiro, Brazil - 12/08/2016. Almaz Ayana (ETH) of Ethiopia celebrates next to Tirunesh Dibaba (ETH) of Ethiopia. REUTERS/Alessandro Bianchi FOR EDITORIAL USE ONLY. NOT FOR SALE FOR MARKETING OR ADVERTISING CAMPAIGNS.
Picture Supplied by Action Images

2016 Rio Olympics - Athletics - Victory Ceremony - Women's 10,000m Victory Ceremony - Olympic Stadium - Rio de Janeiro, Brazil - 12/08/2016. Gold medallist Almaz Ayana (ETH) of Ethiopia, silver medallist Vivian Jepkemoi Cheruiyot (KEN) of Kenya and bronze medallist Tirunesh Dibaba (ETH) of Ethiopia pose with their medals. REUTERS/Alessandro Bianchi FOR EDITORIAL USE ONLY. NOT FOR SALE FOR MARKETING OR ADVERTISING CAMPAIGNS.
Picture Supplied by Action Images

2016 Rio Olympics - Athletics - Victory Ceremony - Women's 10,000m Victory Ceremony - Olympic Stadium - Rio de Janeiro, Brazil - 12/08/2016. Bronze medallist Tirunesh Dibaba (ETH) of Ethiopia poses with her medal. REUTERS/Alessandro Bianchi FOR EDITORIAL USE ONLY. NOT FOR SALE FOR MARKETING OR ADVERTISING CAMPAIGNS.
Picture Supplied by Action Images

2016 Rio Olympics - Athletics - Victory Ceremony - Women's 10,000m Victory Ceremony - Olympic Stadium - Rio de Janeiro, Brazil - 12/08/2016. Gold medallist Almaz Ayana (ETH) of Ethiopia, silver medallist Vivian Jepkemoi Cheruiyot (KEN) of Kenya and bronze medallist Tirunesh Dibaba (ETH) of Ethiopia pose with their medals. REUTERS/Alessandro Bianchi FOR EDITORIAL USE ONLY. NOT FOR SALE FOR MARKETING OR ADVERTISING CAMPAIGNS.
Picture Supplied by Action Images

Athletics - Rio 2016 Olympic Games – Women’s 10,000 meters training - Addis Ababa, Ethiopia – 26/7/16 – Tirunesh Dibaba flexes. REUTERS/Tiksa Negeri

Athletics - Rio 2016 Olympic Games – Women’s 10,000 meters training - Addis Ababa, Ethiopia – 26/7/16 – Tirunesh Dibaba flexes. REUTERS/Tiksa Negeri

Athletics - Rio 2016 Olympic Games – Women’s 10,000 meters training - Addis Ababa, Ethiopia – 26/7/16 – Tirunesh Dibaba runs. REUTERS/Tiksa Negeri

Athletics - Rio 2016 Olympic Games – Women’s 10,000 meters training - Addis Ababa, Ethiopia – 26/7/16 – Tirunesh Dibaba runs. REUTERS/Tiksa Negeri

Tirunesh Dibaba of Ethiopia crosses the finish line to win the women's 5000 metres race during the IAAF Diamond League athletics meeting at the Stade de France Stadium in Saint-Denis, near Paris, France, July 4, 2015. REUTERS/Stephane Mahe

Almaz Ayana of Ethiopia competes ahead of her compatriot Tirunesh Dibaba during the women's 5000 metres race during the IAAF Diamond League athletics meeting at the Stade de France Stadium in Saint-Denis, near Paris, France, July 4, 2015. REUTERS/Stephane Mahe

Meseret Defar of Ethiopia (L) celebrates as she wins the women's 5000 metres race in front of second placed compatriot Tirunesh Dibaba (R) during the Weltklasse Diamond League athletics meeting in Zurich August 29, 2013. REUTERS/Ruben Sprich (SWITZERLAND - Tags: SPORT ATHLETICS)

Meseret Defar of Ethiopia (L) celebrates as she wins the women's 5000 metres race in front of second placed compatriot Tirunesh Dibaba (R) during the Weltklasse Diamond League athletics meeting in Zurich August 29, 2013. REUTERS/Ruben Sprich (SWITZERLAND - Tags: SPORT ATHLETICS)

Meseret Defar of Ethiopia (L) wins the women's 5000 metres race in front of compatriot Tirunesh Dibaba (R) during the Weltklasse Diamond League athletics meeting in Zurich August 29, 2013. REUTERS/Ruben Sprich (SWITZERLAND - Tags: SPORT ATHLETICS)

Tirunesh Dibaba of Ethopia poses with her gold medal during the women's 10,000 metres victory ceremony at the IAAF World Athletics Championships at the Luzhniki stadium in Moscow August 12, 2013. REUTERS/Grigory Dukor (RUSSIA - Tags: SPORT ATHLETICS)

Silver medallist Gladys Cherono of Kenya, gold medallist Tirunesh Dibaba of Ethopia and her compatriot bronze medallist Belaynesh Oljira (L-R) pose during the women's 10,000 metres victory ceremony at the IAAF World Athletics Championships at the Luzhniki stadium in Moscow August 12, 2013. REUTERS/Grigory Dukor (RUSSIA - Tags: SPORT ATHLETICS)

Gold medallist Tirunesh Dibaba of Ethopia listens to her national anthem during the women's 10,000 metres victory ceremony at the IAAF World Athletics Championships at the Luzhniki stadium in Moscow August 12, 2013. REUTERS/Grigory Dukor (RUSSIA - Tags: SPORT ATHLETICS TPX IMAGES OF THE DAY)

Tirunesh Dibaba of Ethiopia (L) celebrates with teammate Belaynesh Oljira after winning the women's 10,000 metres final during the IAAF World Athletics Championships at the Luzhniki stadium in Moscow August 11, 2013. REUTERS/Kai Pfaffenbach (RUSSIA - Tags: SPORT ATHLETICS)

Tirunesh Dibaba of Ethiopia (R) runs ahead of Belaynesh Oljira of Ethiopia (C) and Gladys Cherono of Kenya in the women's 10,000 metres final during the IAAF World Athletics Championships at the Luzhniki stadium in Moscow August 11, 2013. REUTERS/Dylan Martinez (RUSSIA - Tags: SPORT ATHLETICS)

Tirunesh Dibaba of Ethiopia celebrates her victory in the women's 10,000 metres final during the IAAF World Athletics Championships at the Luzhniki stadium in Moscow August 11, 2013. REUTERS/Lucy Nicholson (RUSSIA - Tags: SPORT ATHLETICS)

Tirunesh Dibaba of Ethiopia celebrates her victory in the women's 10,000 metres final during the IAAF World Athletics Championships at the Luzhniki stadium in Moscow August 11, 2013. REUTERS/Lucy Nicholson (RUSSIA - Tags: SPORT ATHLETICS TPX IMAGES OF THE DAY)

Tirunesh Dibaba of Ethiopia celebrates winning the women's 10,000 metres final during the IAAF World Athletics Championships at the Luzhniki stadium in Moscow August 11, 2013. REUTERS/Dylan Martinez (RUSSIA - Tags: SPORT ATHLETICS TPX IMAGES OF THE DAY)

Tirunesh Dibaba of Ethiopia runs in the women's 10,000 metres final during the IAAF World Athletics Championships at the Luzhniki stadium in Moscow August 11, 2013. REUTERS/Fabrizio Bensch (RUSSIA - Tags: SPORT ATHLETICS)

Tirunesh Dibaba of Ethiopia runs in the women's 10,000 metres final during the IAAF World Athletics Championships at the Luzhniki stadium in Moscow August 11, 2013. REUTERS/Fabrizio Bensch (RUSSIA - Tags: SPORT ATHLETICS)

Tirunesh Dibaba of Ethiopia celebrates after winning the women's 10,000 metres final during the IAAF World Athletics Championships at the Luzhniki stadium in Moscow August 11, 2013. REUTERS/Phil Noble (RUSSIA - Tags: SPORT ATHLETICS)

Tirunesh Dibaba of Ethiopia wins the women's 10,000 metres final during the IAAF World Athletics Championships at the Luzhniki stadium in Moscow August 11, 2013. REUTERS/Phil Noble (RUSSIA - Tags: SPORT ATHLETICS)

Tirunesh Dibaba of Ethiopia celebrates winning the women's 10,000 metres final during the IAAF World Athletics Championships at the Luzhniki stadium in Moscow August 11, 2013. REUTERS/Kai Pfaffenbach (RUSSIA - Tags: SPORT ATHLETICS)

Winner Tirunesh Dibaba of Ethiopia celebrates with compatriot Belaynesh Oljira (R) after the women's 10,000 metres final at the IAAF World Athletics Championships at the Luzhniki stadium in Moscow August 11, 2013. REUTERS/Lucy Nicholson (RUSSIA - Tags: SPORT ATHLETICS)

Tirunesh Dibaba of Ethiopia runs to win ahead of Gladys Cherono (L) of Kenya in the women's 10,000 metres final during the IAAF World Athletics Championships at the Luzhniki stadium in Moscow August 11, 2013. REUTERS/Lucy Nicholson (RUSSIA - Tags: SPORT ATHLETICS)

Tirunesh Dibaba of Ethiopia (L) is kissed by teammate Belaynesh Oljira after winning the women's 10,000 metres final during the IAAF World Athletics Championships at the Luzhniki stadium in Moscow August 11, 2013. REUTERS/Kai Pfaffenbach (RUSSIA - Tags: SPORT ATHLETICS)

Tirunesh Dibaba of Ethiopia wins the women's 10,000 metres final during the IAAF World Athletics Championships at the Luzhniki stadium in Moscow August 11, 2013. REUTERS/Lucy Nicholson (RUSSIA - Tags: SPORT ATHLETICS)

Tirunesh Dibaba of Ethiopia runs in the women's 10,000 metres final during the IAAF World Athletics Championships at the Luzhniki stadium in Moscow August 11, 2013. REUTERS/Dylan Martinez (RUSSIA - Tags: SPORT ATHLETICS)

Ethiopia's Tirunesh Dibaba (C), the women's 10,000 meters gold medallist during the London 2012 Olympic Games, sprints during training in Addis Ababa August 6, 2013 ahead of the 14th IAAF World Championships in Moscow. REUTERS/Tiksa Negeri (ETHIOPIA - Tags: SPORT ATHLETICS OLYMPICS)

Ethiopia's Tirunesh Dibaba poses with her bronze medal for women's 5000m at the London 2012 Olympic Games in London at the Olympic Stadium August 10, 2012. REUTERS/Eddie Keogh (BRITAIN - Tags: SPORT OLYMPICS SPORT ATHLETICS)

Ethiopia's Tirunesh Dibaba poses with her bronze medal for women's 5000m at the London 2012 Olympic Games in London at the Olympic Stadium August 10, 2012. REUTERS/Eddie Keogh (BRITAIN - Tags: SPORT OLYMPICS SPORT ATHLETICS)

Ethiopia's Meseret Defar (L) celebrates with her compatriot Tirunesh Dibaba after winning the women's 5000m final during the London 2012 Olympic Games at the Olympic Stadium August 10, 2012. Dibaba finished third in the event. REUTERS/Kai Pfaffenbach (BRITAIN - Tags: OLYMPICS SPORT ATHLETICS)