The Parador hotel in the Teide national park in the centre of Tenerife is eerily quiet and surreally isolated, 15 miles from the nearest village. It sits in a desert of solidified igneous rock where clearly no farmer has dared set a hoe or graze a sheep. High above rise the vast cone and threatening black lava flows of a volcano that looks dormant rather than extinct. The one road that passes through goes from nowhere in particular to nowhere else, through a hostile wilderness where sudden winds whip up dust storms that sting the eyes and burn the sinuses. There is no tumbleweed blowing past the chapel outside the hotel but there should be.

Four hours flight due south of Britain, on the same longitude as the Sahara, the hotel hosts three kinds of visitors: astronomers who want to take advantage of a lack of light pollution and observe the stars, weekenders who want to escape the stag parties of Playa de las Américas in total solitude, and professional cyclists such as Bradley Wiggins and his Team Sky cohorts. The cyclists come in little groups but in sufficient numbers for the hotel to boast a fully kitted bike room, where the carbon fibre machines hang neatly on hooks, and teams such as Liquigas and Astana have left bike bags and cool boxes ready for their next visit.

One can feel what draws the cyclists as one tries to sleep in the hotel. Breathing does not come easy in the thin, dry air at 2,100m above sea level. The lungs struggle from time to time. The nose and throat burn a little, as if breathing in acid. The hotel is at high altitude and it has drawn a select group of Tour de France contenders over the years. Lance Armstrong has slept here. Maxim Iglinsky, winner of one of the biggest Classics of the spring, Liège-Bastogne-Liège, is breakfasting two tables away from Wiggins and his probable team mates in the Tour: Michael Rogers, Chris Froome, Konstantin Siutsou, Christian Knees and Richie Porte.

The presence of Wiggins and Co can be traced back to the Tour de France of 2010, which the triple Olympic gold medallist describes as "a disaster". He had come into that race under a massive weight of expectation, having just signed with the big-budget new boys of Sky and having finished fourth the previous year, although that happened, he says, without his knowing quite how or why.

In terms of the hopes invested in him he bombed, finishing 23rd, prompting a complete rethink of his approach. "We had no data or information about how I did it, not even a VO2 max test." He invested his trust in two men: one was the former professional Shane Sutton, who had been key to the British Olympic cycling's team's effort in Beijing, "the only person who could tell me exactly how it all was". The second confidant was also Australian, the sports scientist Tim Kerrison, who had trained Olympic swimmers and rowers but knew nothing about cycling when he joined Sky with a brief to look outside the box for ways of improving performance.

Wiggins had struggled in the 2010 Tour whenever the race hit high altitude. With the 2011 race including some of Europe's highest passes, with more kilometres than usual at over 2,500m above sea level, Kerrison decided to begin by focusing on that area of weakness. In January 2011 he visited Tenerife to assess the roads for training. An experimental two-week training camp was followed by the biggest victory of Wiggins's road racing career, the Dauphiné Libéré stage race.

Tenerife, Kerrison explains, provides everything lacking for a Tour contender in Wiggins's home in Lancashire: heat, altitude, 20-mile mountain climbs, and peace and quiet. There is a benefit for athletes merely from being at altitude, which enhances the body's ability to utilise oxygen, but there are other pluses here. "Unlike some high-altitude venues, it's possible to train at sea level, which is less damaging at high intensity; unlike Alpine locations the weather is relatively stable in April and May."

"I said I wanted to train for the Tour without any compromise," Wiggins says. "I'm getting to a point in my career where I want to look back with no regrets." That meant beginning training earlier than usual, training harder from the off and interspersing long training camps with races which have to be tackled flat out, to win. The traditional cycling concept of training through competing has been jettisoned. The new philosophy has given Wiggins two major stage race victories this year – Paris-Nice and the Tour of Romandie – out of the four he has started.

The training schedule Kerrison and Sutton devised began on 1 November 2011. It used data gathered by Kerrison in the 2010 and 2011 Tours, which he believes demonstrates the power outputs an athlete needs to win the race. A graph shows the power output levels against the time they need to be sustained, with a second line showing what Wiggins, or other Sky Tour riders, can achieve relative to what they need to do. The goal is to get the two lines as closely matched as possible. The training programme builds into the latest three-week spell of training through mid-late May, the point where Wiggins takes his form to a level which he hopes will win him the Tour. We visit on a rest day, when he spins his stick-thin legs for 30 minutes to the nearest coffee bar while gossiping on the bike with Rogers, and returns, at a modest pace.

But the previous three days have been six-hour stints, with some 4,000m of vertical climbing per day: he is aiming for a total of 100,000m climbing leading into the Tour. The menu is repeated in subsequent days. Whereas on his previous visit in April the workloads were "mid-range", the levels of intensity, pain and lactate have been increased this time. "Yesterday was 25‑minute efforts in 35C heat, three of them. It's hard to tell a layman what it feels like: it's hard in a very sweet way, all mixed up with the endorphins."

The work is at the near maximal intensity he might adopt in a prologue time trial, followed immediately by what amounts to weight training on the bike, a big-gear effort at low-pedal revolutions, at close to breaking point, all at an oxygen-deprived altitude between 1500m and 2,200m. After a rest he repeats it. All this, Kerrison believes, will prepare Wiggins's legs for the steepest climbs on this year's Tour. "When I came in, people believed Brad was only good up to about a 7% gradient; now he can cope with up to 13%."

"Three of the lads were wasted by the end but you realise that, if you can do that effort now, it's the Tour winner," says Wiggins. "You can hardly breathe but it's the kind of effort that wins the Tour." Such a workload, he emphasises, is possible only after six months' continuous building, to ensure that, when he does the work, his body can cope. He has worked on his upper-body strength and his core fitness, too, to improve his ability to sustain an effort: the result, he and Kerrison believe, is victories such as his unexpected sprint-stage win in Romandie.

Back at the hotel another attraction is clear: isolation. "When you are training as hard as we are it's nice to have no distractions. You don't end up sitting at a computer while you rest, you do basic things like reading a book or watching a DVD. It's very peaceful." The phrase "living like a monk" is often used to describe an athlete's total focus; here there is truly something monastic about Wiggins's reclusiveness where, as Rogers puts it, "anything could happen in Europe and you'd never know".

Wiggins feels it will be worth it. "After 2009 I didn't really believe I could win the Tour. I thought, 'That's for someone else, kids from Kilburn don't win the Tour.' But I really believe I can win it now." If he does, or merely comes closer than any Briton has done hitherto, the groundwork has been done here, next to an extinct volcano with only the blue sky and Saharan breeze to distract him.