The gold- and bronze-winning Olympic triathletes talk sibling rivalry on the road to Rio.

As far as sibling rivalries go, there’s none more unique than that shared by the Brownlee brothers, the reigning Olympic gold and bronze medallists in the toughest contest in all of athletics, the triathlon. And that’s because most of the time it isn’t a rivalry at all. It’s a partnership. For 35 hours a week they train side by side, pushing each other forward as they navigate the dales, moors and country roads of their native Yorkshire. When it comes to race day, though, they stand on the starting line the fiercest of rivals.

When MR PORTER visits the brothers in late April, snow – yes, actual snow – is falling on Bramhope, the small village on the southern tip of the Yorkshire Dales that Messrs Jonathan (above left) and Alistair Brownlee (above right) call home. It’s gathering on the hedgerows and drystone walls, lying in drifts on the rolling hilltops and liquefying into puddles of brown sludge under the brothers’ trail-running shoes (a gift from their sponsor, adidas, they get through dozens of pairs each year). It’s landing sharp and cold on the faces of the duo as they run into the wind, heads bent forward, every footstep propelling them further from home and closer to their one common goal: a gold medal in Rio.

Born in Dewsbury, West Yorkshire, to two doctors and educated at the sport-mad Bradford Grammar School, the Brownlees are, without question, the finest triathletes Great Britain has ever produced. That legacy was secured at the 2012 London Olympics with a barnstorming performance: in front of a home crowd with Mr Alistair Brownlee took the gold medal, and Mr Jonathan Brownlee, half a minute behind him, took the bronze. It was the first time that two brothers have shared a podium in an individual sport since 1908.

In Rio this August, Mr Alistair Brownlee, the older of the two at 28, will aim to become the first male triathlete to successfully defend an Olympic title. Mr Jonathan Brownlee, 26, will be doing everything in his power to push his big brother into second place.

But the competition will be fierce – even without their arch nemesis, Mr Javier Gómez, the Spanish five-time ITU World Champion, who dropped out of the Olympics earlier this month after breaking his elbow in a cycling accident. There will be more than 50 other athletes to contend with, maybe 20 of whom, they estimate, are capable of taking home a medal on the day. If either of the Brownlee brothers are to achieve their goals, they can’t let a little adverse weather get in the way of training.

Triathlon is perhaps the most gruelling of Olympic sports, comprising a 1,500m swim – often in choppy, frigid waters – a 40km cycle and a 10km run, with every stage of the race completed at breakneck pace. At the London Olympics, for instance, Mr Alistair Brownlee ran the final leg in a little more than 29 minutes. That’s about a minute and a half longer than it took fellow Brit Mr Mo Farah to win gold in the 10,000m track final. And Mr Alistair Brownlee did it while wearing a wetsuit.

That the Brownlee brothers are able to produce such superhuman performances – anyone who has ever run 10km will appreciate just how fast 29 minutes is, and that’s without a long swim and cycle – is made all the more impressive by the fact that they seem so… well, human. They’re boyish and slight in person, especially Mr Alistair Brownlee, who, at 6ft tall, but weighing just 70kg, looks as if a stiff gust might send him flying. And maybe it’s something to do with their down-to-earth Yorkshire upbringing, but they don’t exactly exude Herculean levels of glamour, either.

“I’ve had days when I’ve come home from a bike ride and my hands have been so cold that I’ve had to open the front door with my teeth,” says Mr Jonathan Brownlee, reflecting on this morning’s unseasonal weather from the warmth of a local hotel. “Days when you’re too cold to get in the shower because if you warm up too quickly you might faint, so you have to get into bed in your clothes first.”

Such is the life, it would seem, of a world champion triathlete. The brothers lead a monk-like existence, with arduous training and severe self-discipline the main constants in their lives. They both live alone, in houses about half a mile from each other. They used to live together, but Mr Jonathan Brownlee moved out after the Olympics in 2012 – “you end up living on top of each other,” he explains. If there’s one area of their lives in which they are allowed to indulge, it’s food, with homemade spaghetti bolognese and golden syrup-drenched flapjacks regularly on the menu. But then, with the number of calories that they burn on a daily basis, you wouldn’t expect them to be too worried about piling on the pounds.

On any given week, the brothers will cover up to 70 miles on foot, mostly at an easy pace. “We only hit full race pace a couple of times a week,” says Mr Alistair Brownlee. “The rest of the time – about 90 per cent –  is just about putting in the hours, working on your technique and training your body to take on more oxygen.” They’ll cover many times that distance on a bike, spending between 15 and 20 hours in the saddle every week. On Thursday nights they join the Leeds Chain Gang, a 50-strong cycling group that counts among its members a few other GB triathletes, including fellow Yorkshireman Mr Gordon Benson. They’ll cover about 40km in around 90 minutes. Twice a week, the brothers go all out with hard, interval-based training on the track and in the pool.

Throw in a couple of physiotherapy and weight-training sessions every week, and it’s understandable that they don’t boast much of a life outside of the sport. The training schedule of a champion triathlete doesn’t allow for that. “It’s hard,” says Mr Jonathan Brownlee. “You push yourself to the absolute limit, in training and in racing.”

What is it, then, that motivates them? “Two things,” says Mr Jonathan Brownlee, by far the more talkative of the two. “First, my brother’s a massive motivation. I remember the day he first came back with his Great Britain kit and dumped it on the kitchen table. I was like, ‘I want that.’ Second, I just love it. Look outside,” he says, gesturing out of the window and across the Yorkshire hills, where the snow is finally thawing in the afternoon sun. “How could you not?

“We do 35 hours of training a week,” he continues. “I don’t think it’s possible to make every hour count if you don’t enjoy it on some level. I strongly believe that we only have a finite reserve of motivation to draw upon every day. If you’re having to spend it on getting out of the door in the morning, you’re going to have less to spend on pushing yourself during training.” For Mr Alistair Brownlee, Britain’s most successful triathlete, there’s an added incentive to succeed. “I don’t think anything can compare to London, to the feeling of winning in front of a home crowd,” he says. “But I’ve got my own personal reasons for wanting to win it. Defending my title, especially with the number of injuries I’ve had, would be something to be proud of.”

Triathlon pushes athletes to the absolute limit of their physical capabilities and there’s only so much the body can take. Mr Alistair Brownlee has been troubled by injuries over the years, with a series of ligament and Achilles-tendon issues affecting his left ankle that have prevented him from challenging for the world title since 2012. Surgery, in August last year, has set him back on the path to his previous form, and in their last two races before Rio – the ITU World Series events in Stockholm and Leeds – a familiar order has been restored, with Mr Alistair Brownlee winning and Mr Jonathan Brownlee coming a close second in both. However, many in the know believe that Mr Jonathan Brownlee now has the edge. A streak of podium appearances lasting from July 2010 to May 2014 – 42 events in a row – attest to this.

But the younger Brownlee also lost time last year to a stress fracture in his femur – “You know when you’ve got a plastic ruler and you bend it too much and it goes white and cracks? It’s like that” – and in a recent event on Australia’s Gold Coast, he succumbed to heat exhaustion with 1km to go. “I was in a hospital bed for an hour afterwards covered in ice,” he says. “I can’t remember finishing the race at all.”

With just weeks left and the main challenger to the Brownlee brothers now out of the frame, it is anyone’s guess which brother will emerge victorious. So what will happen in Rio de Janeiro on 18 August, when the men’s triathlon final is over? Who has won?

“I did. He came second,” the brothers pipe up in tandem.

Whatever happens, one thing’s certain: the weather should be a lot nicer than it was today.