BEIJING, Aug 8: Road cyclists will be the first Olympic endurance athletes to test the impact of Beijing’s notorious pollution, heat and humidity when the men take to their bicycles for a 245-km (152 mile) road race on Saturday.

Spain’s Alejandro Valverde, defending Olympic champion Paolo Bettini and Germany’s Stefan Schumacher are all favourites in the distance event that winds its way from the Forbidden City in ancient Beijing out to the Great Wall.

The men will ride a flat 80 km out of the city then will complete seven laps of a 24-km circuit between the Badaling and Juyongguan sections of the Great Wall. On Sunday the women follow the same route from Beijing but ride two laps of the circuit.

The heat and pollution plus long, hilly portions of the circuit are expected to narrow the field down to only a few dozen cyclists by the finish.

“This is the toughest course I have ever seen at a tournament event,” said Egon Kessel, coach of the Netherlands team.

The route favours strong climbers and countries with larger teams who might be more capable of controlling the race.

“It’ll be hard. It really twists a lot on the uphill,” said American Levi Leipheimer, still coughing as he cooled down from a training ride on Thursday.

“With breakaways or attacks going it’s going to be hard to see and it’s going to be hard to keep track of who’s up the road, who’s attacked,” said Leipheimer.

Like many riders he said the hot weather and pollution would likely have a big impact on the race.

Luxembourg head coach Bernhard Baldinger, whose team includes Kim Kirchen and the Schleck brothers, said countries like his with less than five riders will suffer on the course.

In Beijing, Kirchen and Andy and Frank Schleck will have to work together to get to the podium, unlike one day on the Tour de France when their simmering rivalry became evident when the brothers attacked and tried to drop yellow jersey wearer Kirchen.

On the women’s side, Germany’s Judith Arndt is one of the favourites in the road race as she tries to better her silver medal performance from Athens. Australia’s Oenone Wood, Sweden’s Susanne Ljungskog and France’s veteran Jeannie Longo-Ciprelli — who at 49 is in her seventh Olympics — are her top rivals.

American Kristin Armstrong, the 2006 time trial world champion, used a high-tech way of preparing for the course.

During an event in Beijing last year she plotted the course on GPS then created and trained on a similar route in her hometown.

The time trial favourite who is also competing in the road race, Armstrong said she liked the hilly course.

Her toughest competition in the time trial, which involves one lap of the circuit at the Great Wall, include Marianne Vos of the Netherlands, Arndt and Switzerland’s Karin Thurig. In the men’s two-lap time trial, Schumacher will be challenged by Leipheimer and Spain’s Alberto Contador — who are both fresh after sitting out the gruelling Tour de France.

Road cycling races begin on Saturday and end on Wednesday.—Reuters