Updated

When Alistair Brownlee made his bid for glory on the run leg of the 2008 Olympic triathlon few were surprised when the 20-year-old upstart was swallowed up by the chasing pack three kilometers from the line.

If the Briton finds himself in a similar position in this year's Games the field will know they are racing for silver.

All of them, that is, apart from his two-years younger brother Jonathan, who has emerged from his position as Alistair's wing man and regular podium partner into a true gold medal contender himself.

Ranked one and two in the world, the duo have had such an enormous impact on the sport that even people with the pedigree of former Olympic champion Simon Whitfield and Spain's former double world champion Javier Gomez say they have had to change the way they approach races.

That is because of the brothers' ability to go full bore on the 1500 meters swim and 40-kilometre bike legs and still be able to tear into the 10 kilometers run at a pace nobody can live with.

"Usually I would play what's called sit and kick - you'd better get rid of me or I'm going to out-kick you," said Canadian Whitfield who did just that to win the inaugural Olympic triathlon in Sydney in 2000.

"But the Brownlee brothers changed the game. If you run this Olympic race 10 times, one of them will win it nine times. But they won't win it that 10th time and you try to be that person to be there to capitalize on it that 10th time."

Whitfield, a surprise winner in Sydney and silver medalist in 2008, is testament to the fact that the Olympic triathlon has never gone to the race favorite. But nobody has ever gone into a Games on such a roll as Alistair Brownlee.

In 2009 he lifted the world title by winning all five of the season's championship races he entered, a remarkable achievement in a sport where so many factors can influence the result on any given day.

He was world champion again last year, highlighted by a dominant display in the London Olympics test event on the course that will largely be used for the 2012 race.

BLISTERING RUN

Jonathan produced a blistering run to finish third in that event and the pair have also had a number of notable one-two finishes. This year, with Alistair's season delayed by an Achilles injury, Jonathan stepped up to the plate in style by winning the first two world championship races.

The brothers share a house in a village in Yorkshire, northern England, train and relax together and, when they can, try to help each other in races.

Every mother's dream sons-in-law, they are modest, polite and respectful of their opponents yet they both have a fierce competitive instinct and a massive capacity to work hard and suck up the pain.

While most elite triathletes relocate to warmer climes for winter training camps, the Brownlees prefer the home "comforts" of hammering up their local hills in driving wind and rain.

Their success has, of course, catapulted them into the public eye as they are listed as potential British medalists but the straight-talking duo say they will approach the biggest day of their lives on August 7 in the same way they would the local club cross-country runs they race in through the winter.

"Olympics, worlds, hometown, favorite - any race - I don't care, I just go out and race," Alistair told Reuters.

Looking back to his Beijing experience, where he eventually finished 12th, he said: "I tried as hard as I could then blew up and was quite happy with that.

"That's how I've always raced, whether it's swimming, running or triathlon - I just go for it."

The London course, with no hills and just a few technical twists and turns, suits the Brownlees as it means it will be hard for any group to make much of a break on the bike leg.

If anyone does manage to open a gap, they will set off on the run fully aware that the Brownlees, roared on by their home fans, will be closing on them with every step.

While Jonathan, who won the world sprint distance championship last year, is clearly in hot form, the one unknown factor at this stage is Alistair's fitness.

The torn Achilles was a pretty serious injury. He was forced to wear an air boot for three weeks and was restricted to pool and gym work for months.

He returned to action in early June where he crossed the line together with Jonathan in a low-key British race but the real test will come in his first world championship race in Kitzbuehel, Austria next weekend.

"It was hard to go without running for so long but at least I've had a decent rest," he said.

"Hopefully, I'll come back fully refreshed."

(Editing by Ed Osmond)