Best of the World Athletics Championships

Britain's Toby Harries and Rabah Yousif, Italy's Vladimir Aceti and Matteo Galvan and France's Christopher Naliali and Thomas Jordier in action during the men's 4x400 relay final at the World Athletics Championships in Doha. REUTERS/Fabrizio...more

Poland's Iga Baumgart-Witan, Patrycja Wyciszkiewicz, Malgorzata Holub-Kowalik and Justyna Swiety-Ersetic celebrate winning silver in the women's 4x400 relay final. REUTERS/Hannah Mckay

Nia Ali of the U.S. crosses the finish line winning gold, Kendra Harrison of the U.S. winning silver and Jamaica's Danielle Williams winning bronze in the women's 100 meter hurdle final. REUTERS/Pawel Kopczynski

Ukraine's Maryna Bekh-Romanchuk celebrates winning silver in the women's long jump final. REUTERS/Dylan Martinez

Jamaica's Tissanna Hickling in action during the women's long jump. REUTERS/Dylan Martinez

Dezerea Bryant of the U.S. celebrates winning bronze in the women's 4x100 relay final. REUTERS/Lucy Nicholson

Uganda's Fred Musobo during the men's marathon. REUTERS/Lucy Nicholson

Britain's Asha Philip, Dina Asher-Smith, Ashleigh Nelson and Daryll Neita celebrates winning silver in the 4x100 relay final. REUTERS/Dylan Martinez

Kenya's Hellen Obiri and Margaret Chelimo Kipkemboi after the women's 5000 meter final. REUTERS/Fabrizio Bensch

Colombia's Caterine Ibarguen reacts in the women's triple jump final. REUTERS/Dylan Martinez

Estonia's Maicel Uibo reacts during the men's decathlon 1,500 meters at the World Athletic Championships in Doha, Qatar. REUTERS/Lucy Nicholson

Germany's Niklas Kaul in action during the men's decathlon javelin throw. REUTERS/Hannah Mckay

Ethiopia's Teddese Lemi falls during the men's 1,500 meters heats. REUTERS/Lucy Nicholson

Germany's Niklas Kaul in action during the men's decathlon pole vault. REUTERS/Dylan Martinez

Burkina Faso's Marthe Koala in action during the women's heptathlon long jump. REUTERS/Dylan Martinez

Bahrain's Salwa Eid Naser during the women's 400 meters final. REUTERS/Fabrizio Bensch

France's Pascal Martinot-Lagarde celebrates winning bronze in the men's 110 meters hurdles final. REUTERS/Ahmed Jadallah

Poland's Justyna Swiety-Ersetic reacts after finishing second in her semi final during the women's 400 meter. REUTERS/Lucy Nicholson

Noah Lyles of the U.S. celebrates winning gold in the men's 200 meter final. REUTERS/Hannah Mckay

Sam Kendricks of the U.S. in action during the men's pole vault final. REUTERS/Dylan Martinez

Britain's Dina Asher-Smith in action during the women's 200 meter semi finals. REUTERS/Aleksandra Szmigiel

Belarus' Tatsiana Khaladovich during the women's javelin throw final. REUTERS/Kai Pfaffenbach

Turkey's Ozkan Baltaci competes in the men's hammer throw qualification. REUTERS/Kai Pfaffenbach

Sweden's Armand Duplantis in the men's pole vault final. REUTERS/Dylan Martinez

India's Avinash Sable and Athlete Refugee Team's Otmane Nait Hammou in action during the men's 3000 meter steeplechase heats. REUTERS/Lucy Nicholson

Uganda's Benjamin Kiplagat in action with Morocco's Mohamed Tindouft during the men's 3000 meter steeplechase heats. REUTERS/Kai Pfaffenbach

Qatar's Mariam Mamdouh Farid in action during the women's 400 meter hurdles heats REUTERS/Ahmed Jadallah

Jamaica's Shelly-Ann Fraser-Pryce holds her son Zyon as she celebrates winning gold in the women's 100m final. The Jamaican claimed her fourth world championship gold medal in the distance to go along with two Olympic golds and perhaps more to come...more

Jamaica's Shelly-Ann Fraser-Pryce crosses the finish line to win gold in the women's 100m final. REUTERS/Ibraheem Al Omari

Poland's Kamila Licwinko in action during the women's high jump final. REUTERS/Pawel Kopczynski

Ethiopia's Muktar Edris celebrates after winning gold with Ethiopia's Telahun Haile Bekele who finishes fourth in the men's 5,000m final. REUTERS/Kai Pfaffenbach

France's Pascal Martinot-Lagarde prepares to compete in the men's 110 meter hurdles heats. REUTERS/Lucy Nicholson

Norway's Karsten Warholm kisses a hurdle as he celebrates winning gold in the men's 400m hurdles final. REUTERS/Dylan Martinez

Ariana Ince of the U.S. in action in women's javelin throw qualification. REUTERS/Dylan Martinez

Christian Coleman of the U.S. celebrates winning gold in the men's 100m final. REUTERS/Ahmed Jadallah

Sweden's Angelica Bengtsson in action during women's pole vault final. REUTERS/Dylan Martinez

Christian Coleman of the U.S. crosses the finish line in the men's 100m final. REUTERS/Fabrizio Bensch

China's Hong Liu crosses the line to win gold in the women's 20km race walk. REUTERS/Kai Pfaffenbach

Brian Williams of the U.S. in action during the men's discus throw qualifications. REUTERS/Kai Pfaffenbach

General view of the start of the women's 100m final race. REUTERS/Fabrizio Bensch

Cuba's Yarisley Silva in action during the women's pole vault final. REUTERS/Hannah Mckay

Cuba's Yarisley Silva during the women's pole vault final. REUTERS/Dylan Martinez

Sandi Morris of the U.S. in action during the women's pole vault final. REUTERS/Kai Pfaffenbach

Gold medalist DeAnna Price of the U.S., silver medalist Poland's Joanna Fiodorow and bronze medalist China's Zheng Wang celebrate after the women's hammer throw final. REUTERS/Fabrizio Bensch

Athletes compete in the women's 10,000m final. REUTERS/Kai Pfaffenbach

General view as athletes compete in the women's 800m semi-finals. REUTERS/Hannah Mckay

Poland's Joanna Fiodorow in action during the women's hammer throw final. REUTERS/Pawel Kopczynski

Poland's Robert Sobera in action during the men's pole vault qualifications. REUTERS/Aleksandra Szmigiel

Ukraine's Iryna Klymets reacts during the women's hammer throw final. REUTERS/Kai Pfaffenbach

Qatar's Abderrahman Samba races out of the blocks at the start of his men's 400m hurdles semi final. REUTERS/Lucy Nicholson

France's Valentin Lavillenie in action during the men's pole vault qualification. REUTERS/Fabrizio Bensch

Czech Republic's Marcela Joglova in action during the women's marathon. REUTERS/Ibraheem Al Omari

Braima Suncar Dabo of Guinea-Bissau helps Aruba's Jonathan Busby during the men's 5,000m heats. REUTERS/Kai Pfaffenbach

Athletes compete in the women's 3,000m steeplechase heats. REUTERS/Kai Pfaffenbach

Kenya's Ruth Chepngetich crosses the line to win the women's marathon. REUTERS/Dylan Martinez