The 31st Summer Olympics starts on August 5 in Rio de Janeiro. Here AFP Sport takes a look at the modern legends of the Games:

Steve Redgrave
The awesome oarsman
The message couldn’t have been any clearer when, at Lake Lanier outside Atlanta in 1996, Britain’s Redgrave declared: “Anybody who sees me in a boat has my permission to shoot me.” Redgrave had, at the age of 34, just won rowing gold for the fourth Games in a row and on live TV, he announced his retirement in unequivocal fashion.
Yet four years later – after being diagnosed with Type 2 diabetes in 1997, and suffering with debilitating ulcerative colitis since before the 1992 Barcelona Games – he put his ailing, 38-year-old body through a punishing training regime one last time and achieved another Olympic triumph, as a member of the coxless fours.
In doing so Redgrave became the only endurance sport athlete to win five golds in five consecutive Games: 1984 (coxed fours), 1988, 1992, 1996 (coxless pairs) and 2000 (coxless fours).His secret? “I decided that diabetes had to live with me, not me live with it,” he said.

Michael Phelps
The most decorated Olympian
A hyperactive child, Phelps was encouraged into swimming aged seven to give his boundless energy an outlet, and became the most decorated Olympian of all time.
The “Baltimore Bullet” came home empty-handed from his first Games at Sydney 2000 when just 15.
But a slew of world records over the next three years led to a dominant display at Athens 2004 as Phelps took six gold and two bronze medals, the second-best performance at an Olympic Games after fellow US swimmer Mark Spitz’s seven golds in 1972.
At Beijing four years later, Phelps claimed the all-time record when in the 4x100m medley relay he completed a haul of eight golds in one Games — seven of them with world record times.
Australian arch-rival Ian Thorpe had prior to Athens said it would be “impossible” to win eight golds – a statement which Phelps kept on his locker as a motivation.
At London four years later he became the most decorated Olympian of all time, taking his total to 18 golds, two silvers and two bronzes.
Having just turned 31, he is aiming to extend his record in his fifth Games this year, having qualified for three individual events at the recent US trials by winning the 100m butterfly, 200m butterfly and 200m individual medley.

Ian Thorpe
The freestyle king
“Thorpedo” won five gold medals, the most by an Australian, with three in his home Sydney 2000 Games (400m free, 4x200m and 4x100m freestyle relays) and two more in Athens (400m free, 200m free) four years later.
At the 2004 Games, Michael Phelps opted to compete in the 200m freestyle in a quest to win a record eight gold medals, which Thorpe called “impossible”. The 200m final was dubbed the “Race of the Century” as Thorpe and Phelps lined up against two former world record-holders, Pieter van den Hoogenband of the Netherlands and Australia’s Grant Hackett.
It proved Thorpe’s greatest victory.
Van den Hoogenband turned more than a second ahead of world record pace at 100 metres but Thorpe was never more than a body length away and chased the Dutchman down in the final 50 metres to take gold in an Olympic record 1min 44.71sec, with Phelps third.
Thorpe could not contain his emotion at his victory as he tore off his cap, punched the air wildly and screamed at the top of his lungs.
Thorpe also won three Olympic silvers and a bronze in his only two Games before retiring at the age of 24 in 2006.
An ill-fated comeback attempt saw him fail to make the cut for London 2012.

Michael Johnson
The one-lap master
The American dominated the 200m and 400m sprints in the final decade of the 20th century, winning four gold medals in the Barcelona (1992), Atlanta (1996) and Sydney (2000) Games.
His tally could have been five as he was part of the 4x400m US relay team that crossed the line first in Sydney but was stripped of the title eight years later, after Antonio Pettigrew admitted doping.
Johnson, always a vehement voice against doping, returned his medal as he felt he had not won it legitimately.
He was nevertheless the only man to win 400m gold twice (1996, 2000) and also won a 4x400m relay gold in 1992 and a 200m gold in Atlanta four years later when he smashed his own world record (19.66) by more than three-tenths of a second with a scarcely believable 19.32sec in the final – the largest improvement in a 200m world record in history.
Usain Bolt has since lowered the mark, but Johnson’s 400 metres world record of 43.18sec set in Seville in 1999 still stands to this day.

Usain Bolt
Lightning that struck twice
The fastest man the world has ever seen, the “Lightning Bolt” shot to worldwide fame in Beijing in 2008 as the first man to do the 100m-200m sprint double since American Carl Lewis in 1984, and then became the first in Olympic history to repeat the feat with his London triumphs.
Not only that, in Beijing the lanky, laid-back Jamaican smashed world records in both sprint finals and he went on to lower the 100m and 200m marks a year later, to 9.58sec and 19.19sec respectively.
He also anchored Jamaica’s 4x100m sprint relay team to gold in both Games, also in world record times.
With six golds already, Bolt is aiming at an unprecedented “treble-treble” in Rio which, if achieved, may never be matched. He has also won a record 11 world championships gold medals since 2009.