Heffernan determined to bow out in a blaze of glory
Like a good wine, race walkers mature with age. Even though he is 38 and appearing in his fifth Olympics, Rob Heffernan is arguably still near the peak of his career.
But his form in the last 24 months has slipped from the heady heights he scaled in the 12 months between August 2012 and 2013 when he finished fourth in the 50km walk at the London Olympics before winning the World championship title in Moscow 12 months later.
His fourth place finish in London was later upgraded to third after the winner Sergey Kirdyapkin from Russia was given a retrospective doping ban.
Heffernan's upgrade secured Ireland's first Olympic medal in walking but the Togher man opted to postpone the official presentation of the medal until after the Rio Games.
Psychologically and emotionally there is a world of difference between being presented with a medal four years after the race and being part of the official Olympic marathon presentation ceremony.
Winning a medal today in the 50km walk in Rio would represent the perfect finale to Heffernan's remarkable career which in terms of the Olympics began in Sydney 16 years ago when he finished 38th in the 20km walk.
The Russians, of course, are banned here but a quality field will tackle the gruelling event, which is being held on a two-kilometre circuit along the coast next to Pontal island, in the Rio suburb of Barra de Tijuca.
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Slovenia's Matej Toth, who dominated last year's 50km race at the World championships in Beijing, has reportedly recovered from a tibia injury which threatened his participation in the Games.
World record-holder Yohann Diniz is back in shape, having missed most of the 2015 season with injury. The Frenchman, who led the 2015 world list with 3:37.48, is aiming to finally secure an Olympic medal - he failed to finish in 2008 and was disqualified four years later in London.
Like Heffernan, Australian Jared Tallent is one of the most consistent and durable performers on the circuit. He finished second on the day to Kirdyapkin in London four years but like Heffernan he was later upgraded and goes into the event as the defending Olympic champion.
He is a multiple Olympic medal winner in the event. Indeed, he is aiming to become the first Australian man to win four medals in athletics, having also secured silver and bronze in the 50km and 20km events in 2008.
Tallent was due to contest the 20km walk in Rio but after aggravating a hamstring injury opted to focus on the 50km, which suggests that he might be short of his best.
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The other threats to Heffernan's ambitions come in the form of the two Chinese, Yu Wei and Wang Zhendong, winner of their Olympic trial with a personal best of 3:41.02, and Japanese pair Takayuki Tanii and Hirooki Arai, who finished fourth and fifth at last year's World championships, relegating Heffernan to sixth place. It was creditable performance for the Cork native, who dropped out of the European championships the previous year.
But if Heffernan could fashion another performance like he did in London when he set a national record of 3:37.54 - an incredible seven and a half minutes inside his previous personal best - a treasured podium finish is within his grasp.
Ireland have two other walkers in today's event: Brendan Boyce, who finished 29th in the London Olympics, and English-born Alex Wright, who is coached by Heffernan and finished 46th in the 20km walk here.