Italy’s reigning champion Paolo Bettini saddled up here Saturday for the men’s road race which is set to be the first big endurance test of the Olympic Games.

Bettini, who won gold in Athens four years ago, is also a two-time world champion having won the rainbow jersey in 2007 and 2006.

Winning gold in the men’s road race, held over a challenging 245km course which finishes at the magnificent setting of the Great Wall, would make him the first ever cyclist to win two Olympic road race titles and two world titles.

Bettini, however, faces a stiff test of his bike racing skills – especially with mist shrouding the final part of the course which is composed of a hilly, 23.8km loop to be raced seven times.

Temperatures were mild on Saturday morning although they are expected to rise throughout the day. A race of attrition – with the pace of the stronger teams whitlting down the contenders – is expected.

“It’s a very hard course, very draining and the (10km) climb is about half an hour in length,” said Stuart O’Grady, one of the Australian team, after training on Thursday. “We were just sweating incredible amounts. I have been in more humid conditions. But if it’s hot here, it will be tough on Saturday.”

The first section of the race is 78.8km long and over slightly undulating terrain. Breakaways are likely, although they are likely to be reeled in on one of the seven ascents of the main loop.

Bettini’s Italian team is one of the strongest in the race, which is composed of 143 riders. However they face a stiff challenge from the Spanish team of Alejandro Valverde, a strong Australian contingent containing two-time Tour de France runner-up Cadel Evans and the Luxembourg team of Kim Kirchen and the Schleck brothers Andy and Frank. Germany’s Stefan Schumacher also comes into the race on top form, and like the Spaniards, Italians and Germans has four teammates at his disposal.