Allyson Felix aiming to overcome her 'heart aches'

The golden girl of US athletics is competing at her fourth Olympic Games at Rio 2016. However the triple gold medallist at London 2012 says her “heart aches” as she will not be able to defend her 200m title in Rio after failing to qualify. She will now have all her reserves focused on defending her 400m crown and is in good stead after running the fastest time in 2016, while she could also go in the 4x100m and 4x400m relays.

USA names powerful track and field team for Rio 2016 Games

Dafne Schippers ready to capitalise

During the heptathlon event at London 2012 the Dutchwoman clocked a scorching 22.83 in the 200m, making her the third-fastest woman in history. She is also the fastest woman this year over the distance. And with defending champion Allyson Felix failing to qualify for the 200m this time around, she has every chance of securing gold at Rio 2016 as well as being a strong contender for the podium in the 100m.

Mo Farah set to bring back the 'Mobot'

The reigning Olympic champion in the 5000m and 10,000m, the Briton is aiming for another historic Olympic double in Rio de Janeiro. Since his triumph at London 2012 – where his famous 'Mobot' celebration was among the highlights – the 33-year-old has become world champion in the two events twice, in 2013 and 2015. Breaking David Moorcroft’s 34-year-old British 3000m record in June this year, Farah looks to be in fine form ahead of Rio 2016, for which he said he has been putting his body "through hell".

Ashton Eaton v Ashton Eaton

Another strong gold medal hope for the USA, the world-record holding decathlete is almost in a league of his own. He is the current Olympic and world champion and it seems his only competition is himself. After becoming the second person in history to break the 9,000 point barrier in 2012 with 9,039, he beat his own record with 9,045 at the 2015 world championships in Beijing.

(Photo: Getty Images/Andy Lyons)

Refugee heroes

A first in Olympic history, the Refugee Olympic Team will have six competitors in the athletics at Rio 2016: five South Sudanese track runners and Ethiopian marathon runner Yonas Kinde. While all of them have clocked times to put them among the Olympic athletes, Kinde is perhaps the best hope for a medal as he has won several marathons in Europe since he moved to Luxembourg in 2013.

(Photo: Getty Images/Paul Gilham)

Bolt v Gatlin

Ali v Foreman, Borg v McEnroe, Coe v Ovett... everybody loves a sporting rivalry and this is defintely the big one of Rio 2016. Will Bolt win the 100m, 200m and 4x100m again and achieve that “triple triple”? Or will Gatlin, who has constantly been at Bolt’s heels and has run the fastest time this year, spoil the party?

Justin Gatlin vows not to get ‘sucked into the hype’ against Usain Bolt at Rio 2016

(Photo: Getty Images/Andy Lyons)

De Grasse and Bromell

With Bolt and Gatlin set to bow out of athletics after Rio 2016, Andre De Grasse of Canada and Trayvon Bromell of USA are perhaps the two that will take up the mantle. Both 21, they finished tied in third place behind Bolt and Gatlin at the 2015 world championships and could be set to come of age at Rio 2016.

(Photo: Getty Images/Ian Walton)

Fabiana Murer's shot at redemption

Brazil has few athletics medal contenders as the country traditionally does well in other disciplines, but host nation heroes are crucial for any Games and Murer represents Brazil’s best hope in the sport. The 35-year-old pole-vaulter is the current world silver medallist. At Beijing 2008, officials misplaced her equipment and she had to borrow to compete, eventually finishing 10th. At London 2012 she missed out on the final. Rio 2016, in front of a home crowd, could finally be her chance to get an Olympic medal.

(Photo: Getty Images/Alexandre Schneider)

Jessica Ennis-Hill looking for the mother of all comebacks

The British heptathlon star, the poster girl of London 2012, took a hiatus from competing due to injury and the birth of her son Reggie in July 2014. Injury problems have persisted in 2016 and she missed the indoor season, but she will be buoyed by a convincing win at the 2015 world championships where she saw off arguably her closest competition, Brianne Theisen-Eaton of Canada.

Stars of Great Britain’s ‘Super Saturday’ set for Rio return

Eliud Kipchoge's unstoppable transition

The Kenyan is the most dominant marathon runner in the world right now, even though he is relatively new to the event. After switching from track running to the road in 2012, he has won six of his seven marathons, including an impressive victory at the 2016 London Marathon where his finishing time of 2:03:04 was just eight seconds behind the world record.

(Photo: Getty Images/Harry Hubbard)

Vashti Cunningham to leap into history

After winning gold at the World Indoor Championships in March, the 18-year-old high-jumper is in contention to become the youngest female American track and field athlete to win an Olympic medal in 60 years. She is also the daughter of retired NFL quarterback, Randall Cunningham.

(Photo: Getty Images/Andy Lyons)

Can 'the Beast' bite back?

While there is so much talk of Bolt and Gatlin, we cannot afford to forget about Bolt’s compatriot, who is also the second fastest man in the world with a 100m time of 9.69 seconds. Blake, whose nickname is 'the Beast', has been plagued with injury in recent years but when in form he can certainly push Bolt all the way to the wire in the 100m and 200m. He will also run in the 4x100m, so is well in contention of becoming a triple medallist at Rio 2016.

(Photo: Getty Images/Andy Lyons)

Pocket Rocket after her own triple

We also cannot forget that the Jamaican women are a dominant force on the track and Fraser-Pryce has been leading the charge since Beijing 2008. With a gold in the 100m and then again at London four years later she is going after a triple of her own. The five-foot-tall ‘Pocket Rocket’, as she is known, has also been hailed as the best female sprinter of all time by Olympic legend Michael Johnson thanks to her achievements and consistency.

Three athletes seeking unique triples on opening day of Rio 2016 athletics competition

Triple vision from Estonia

Understood to be the first identical triplets to compete at the Olympic Games, the 30-year-old Luik sisters - Leila, Liina and Lily - will all be competing together in the marathon. The sisters from Estonia, who have called their Olympic campaign 'Trio to Rio', only started running competitively six years ago, but all three of them demonstrated a talent for long distance. They are not likely to get near the podium but they will be making history at Rio 2016 nonetheless.