One way or another a Brownlee looks likely to win the triathlon

Meeting Alistair and Jonny Brownlee, certain words come irresistibly to mind – symbiotic is an obvious one, along with sweet (the word no grown man wants to hear), funny, charming, grounded, sorted.

But later, after a little more reflection, there's just no getting away from it – the lexicon unwillingly widens to include contradictory, puzzle and ... Miliband.

Brownlee Major and Minor are old hands at hearing this amateur psychology. It is difficult to imagine that brothers aged 23 and 21 can be veterans of anything very much, yet these days the two of them barely notice the undisguised stares of fascinated observers keen to deliver their supposed insight. But as one such, you can't help yourself. It is not merely that these two sons of Yorkshire are among the very best triathletes in the world, nor yet that they also train and even live together. Most intriguing is the paradox of their unbreakably twinned mindset in an individual sport.

Much of this hinges on the present state of competitive play between them. As the older brother,Alistair is clearly the higher achiever.The world champion two years ago, he successfully defended his European crown in June and has won six of his seven outings this year. Jonny, last year's under-23 world champion, is very much on his way up. He has beaten his brother twice to date, but dismisses both wins as invalid because one was the result of a puncture and in the other Alistair fell during the run. They race each other today over next year's Olympic course – 1,500m of swimming, 40K on the bike and then a 10K run – at the Dextro Energy Triathlon in London's Hyde Park.

"We know people are fascinated by us,'' grins Jonny casually. "Our situation is unique. But it's not odd to live so closely and then compete against each other. I can't imagine anything else."

So far, so straightforward, right? Yet only an hour earlier, Jonny told another interviewer: "If anything, the closeness makes me want to beat Alistair a bit less. Racing against him feels a little bit strange sometimes. And he is better than me."

You have to wonder about the wider implications of that mental conflict. Alistair, as one of the outright favourites for Olympic gold next year, has no doubt of his place in the pecking order. But it seems thornier for Jonny. When Alistair fell during the run in the Sydney triathlon this year, Jonny reached out to him and hesitated, plainly in two minds whether to stop and help him up. Furthermore, in the European championships in Pontevedra, Spain, this June, when Alistair had a potentially race-wrecking puncture, Jonny helped slow the field to allow Alistair not only to catch up but take gold. They are both mystified by the idea this might be unfair.

But then Alistair states: "If Jonny hadn't done that, he would have gone on to win." And Jonny nods. Neither displays any visible concern. At such moments you can't help pondering the sibling dynamic. In tennis, the American twins Bob and Mike Bryan have won 11 Grand Slam doubles titles including last month's Wimbledon. But when they played singles in their teens, so catastrophic was the notion of facing one another across the net that they took it in turns to scratch whenever they were drawn to play in a tournament.

"I can't relate to that," says Alistair, baffled. "It's been a massive advantage for us. People talk of pressure but I don't want my little brother to beat me, and that's real pressure. It's made me very mentally tough."

Jonny nods – but it does seem he is, at best, differently tough. Ask each if he considers himself an individual competitor, and the answer is no.

"We work together," says Alistair. "We help each other in races. If it had been Jonny who had the puncture. I would have done the same for him.'' But it never has been Jonny who has had a puncture, or who has fallen.

Alistair largely declines to discuss the looming Olympic Games until he has definitely qualified. Jonny is less measured, confessing he thinks of the Olympics "all the time".

For a while it feels it would be hard to find a less messed-up pair if you tried. But then later, you remember Jonny contradicting himself on what he calls the "weird" concept of beating his brother, and you find yourself thinking – what if they make it a Brownlee one-two on the Olympic podium... except it's another Miliband scenario, where Alistair/David is relegated to second?

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