As we continue our countdown to the start of the IAAF World Athletics Championships Doha 2019, we look at a quintet of special athletes who defied age and logic to be crowned world champions in their teenage years.

Can anyone stop Mary Keitany? That’s the chief question ahead of the TCS New York City Marathon on Sunday (5), where the current queen of the marathon will seek to win a fourth straight title at the IAAF Gold Label Road Race.

Ghirmay Ghebreslassie of Eritrea and three-time defending women’s champion Mary Keitany of Kenya, will lead the international field at the 2017 TCS New York City Marathon, an IAAF Gold Label Road Race, on 5 November.

Mary Keitany became the first woman this century to win three consecutive New York City Marathon titles on Sunday (5), winning the IAAF Gold Label Road Race in 2:24:26, a full 3:34 ahead of second place.

Many people’s favourite for the men’s marathon will inevitably be be Kenya’s Eliud Kipchoge.

Eritrea’s world marathon champion Ghirmay Ghebreslassie will try to take his personal best for the half marathon under one hour at the eDreams Mitja Marató de Barcelona on Sunday 14 February.

Last year's Virgin Money London Marathon champion Eliud Kipchoge will take on 2014 champion Wilson Kipsang when the two Kenyans face each other in this year’s IAAF Gold Label Road Race on Sunday 24 April, organisers announced on Tuesday (19).

Ghirmay Ghebreslassie was a surprise winner of the men’s marathon title at the IAAF World Championships, Beijing 2015. We chat to the Eritrean teenager to find out more about the gifted 19-year-old gold medallist.

Sixteen years after Haile Gebrselassie made history by becoming the first runner to win four world titles in the 10,000m, his near-namesake Ghirmay Ghebreslassie was in the spotlight in the opening competition of the IAAF World Championships, Beijing 2015.

In the end it was the day of Ghirmay Ghebreslassie. The teenager won Eritrea’s first World Championships gold medal, taking the men’s marathon title on a day when more favoured runners wilted in the sun.

With little more than a week to go to the 2014 IAAF World Half Marathon Championships in the Danish capital of Copenhagen on 29 March, we take a look at some of the key contenders, as well as some of the more interesting entrants.