The environs of Cornebarrieu in the south of France. As locations go, it is pretty much ideal for the two-wheeled athlete. Birch-lined avenues, smoothly-asphalted country roads threading their way through lush green fields. Sleepy, sandstone-coloured villages where the sole signs of life are the chirping of crickets basking in humid, cloudless conditions.

Away from nearby Toulouse, things are close to perfect. No traffic. Ideal weather. Flawless roads, with only slight undulations to interrupt the rhythm of pedalling. Want something more intense? The Pyrennes lie but a brief trip away to the south. Under the circumstances, little wonder that so many professionals live in the surrounding region.

The two cyclists move fluidly, pedalling on these quiet roads with a smooth, almost effortless manner honed by thousands of training miles. Slender, tanned and dressed in the bright yellow colours of the Linda McCartney team, they move along engaged in conversation and at ease with the world. Theirs is a training ride without haste; in four days time they face the toughest test of their careers. Time enough for urgency.

So today they cruise, side by side. Wind at their backs, rising from the saddle when the road slopes upwards. Keeping the pressure off the legs, easing out well-defined muscles and generally conserving energy. A normal training spin is five, maybe six hours; today they steer for home after just two. Then a shower, some good food, maybe catch some more sun in the afternoon. Sometimes it seems an easy existence being a professional cyclist.

SUCH a fallacy is shattered, however, at about four o'clock this afternoon when the first of 198 competitors sprints down the starting ramp of the prologue time trial of the Tour of Italy. A flat out six-kilometre effort which acts as a precursor to the savagery lying ahead; over the next three weeks the riders will cover over 3,700 kilometres (averaging over 110 miles a day), tackle three time trials, including the torturous ascent of Sestrieres and spend 11 days slugging it out in the mountains. Throw in the 140-mile marathon stage to Prato on day seven, five mountain top finishes, and you begin to appreciate the severity of the race.

Blood, sweat and gears. To non-cyclists the Tour de France is where their comprehension of the sport begins and ends, a snapshot of human suffering relayed to television screens each July. But to those who understand the sport, the Giro d'Italia is almost on a par with cycling's great race. Slightly longer (3757 kilometres, as opposed to the Tour's 3430), with one extra day's racing and more time in the mountains, on paper at least it is a harder test. Where the Tour stands out is that more of the world's top riders dispute the race, a reflection of its prestige and importance as a sporting event. It is, as famously described by Sean Kelly, the 110 per cent race.

Notwithstanding the importance of the Tour, however, the Giro d'Italia is a similarly huge, athletically demanding event. Today almost 200 of the world's top cyclists line out at the start in the Vatican, harbouring dreams of a stage win and aspirations of reaching the finish in Milan on June 4th. In a race as difficult as this one, either is a major achievement.

So, too, the fact that for the first time in seven years, an Irish rider will be part of the peloton disputing one of the three major tours. Two years ago Waterford cyclist Ciaran Power won Ireland's national tour, the nine-day FBD Milk Ras. Last year he placed in the top 10 on five stages of the pro-am, seven-day Prutour race in England. Five months ago, he turned professional with the burgeoning Linda McCartney squad and after strong performances in early season races finds himself slotted neatly into their nine-man squad for the Tour of Italy.

As learning curves go, this one comes complete with vertigo warnings. Getting the nod as a first-year professional is almost unheard of these days, thus breeding pragmatic analysis rather than flights of fancy. "It is unbelievable to get into the Tour of Italy, especially as a first year pro," says the 24-year-old. "I am looking forward to it, but for the moment I am just aiming to get through the race as well as I can. If I finish it is going to make me so much stronger for next year and the years after that."

Tipped as a future star by team directeur sportif Sean Yates - a former Tour de France stage winner - Power's main role is to assist the team's two big hitters, Olympic champion Pascal Richard and Atlanta bronze medallist Max Sciandri in the race. Power will also be one of the lead-out men for in-form sprinter Tayeb Braikia, who recorded three top four finishes in the recent Tour of Romandie.

But he, too, has a finishing kick to be proud of, as indicated by high finishes in stages of the Tirreno Adriatico (11th) and the Settimana Cicilista Internazionale (4th) earlier this year. Indeed, Power would have been closer to the podium in the former event had he not been baulked in the final kilometre. "A Politi guy was leading out (top sprinter Jeroen) Blijlevens, then swung off the front. He must have hauled out of the brakes, because he practically stopped. I was all over the bike trying to stay upright and get around him, then got moving again. It definitely slowed me, though," he says.

Being a competent climber - and sure to benefit from a week climbing cols from around the Pyrenean pursuits training camp - Power should get an opportunity to exercise that speed for his own benefit at some stage in the Tour of Italy. "I am sure I will get a chance in the race," he says. "On the later stages where there are some climbs and a group of 70 or so come in together, I am sure that I can be up there and use my sprint."

Realistically, until the likes of EPO, PFC and other such performance enhancers are removed from the sport, Power will always be at a disadvantage. "The tests are a bit of a pain to do," he says about the quarterly blood examinations that all professionals must now undergo, "but hopefully they will work. It would be nice to see how ordinary guys would race".

That he has the raw ability is without question. Competing strongly in pro-am races such as the Prutour and Sun Tour last year while based at home in Ireland, Power's riding this season has earned generous praise from Yates. "He has done excellent so far, he is one of the strong hopes for the team. He has shown not only determination and grit but also the natural requirements of a good rider, namely the ability to ride well in the bunch and to position yourself well, which is half the battle. We are hoping that he is going to progress and be a really good rider."

The assessment is backed up by team manager Julian Clarke, although he does feel that Power needs to believe in himself more: "I think he needs to be a bit more positive about what he can do, because at the moment he tends to say `I'd like to be a really good worker for the team.' But Sean (Yates) is convinced that he is cut out to be a winner."

Time, and future events, will tell if Yates's assessment is correct. In June the Waterford rider targets the Irish national championships, and then looks likely to compete in the Olympic Games in September. For the moment, though, there is the not inconsiderable task of finishing the Giro d'Italia, after which Power will have a much better assessment of his future as a cyclist.

Fact is, three weeks, and 3,700 kilometres of hardship, have a way of teaching you much about yourself. A personal purgatory, but for Power, an essential one.

Blood, sweat and gears. To non-cyclists the Tour de France is where their comprehension of the sport begins and ends, a snapshot of human suffering relayed to television screens each July. But to those who understand the sport, the Giro d'Italia, which starts this afternoon, is almost on a par with cycling's great race.