BEIJING - After all the worries about Beijing's pollution, in the end, withering heat and humidity took a greater toll on Olympic athletes.

Yesterday marked the first outdoor endurance competition of the Games - the grueling 152-mile men's cycling road race that started at the historic Temple of Heaven and wound up at the Great Wall.

The capital's thick haze from the last few days lifted a bit, allowing sunlight through as riders wound their way through the sweltering 61/2-hour race over the hilly course.

What was bad, however, was the heat, and the accompanying humidity resulted in a heat index of 90 degrees. Several riders surrendered long before the gold medal was decided, simply not having the energy to finish the race.

Beijing's air-pollution index logged in at 79, a drop from the day before, though still higher than what the World Health Organization considers healthy.

TV ratings.

The colorful Olympics opening-night ceremony from Beijing on NBC averaged 34.2 million viewers, making it the biggest television event since the Super Bowl.

It was the biggest audience ever for an Olympic opening ceremony not held in the United States, and even eclipsed this year's Academy Awards and finale of

American Idol

, Nielsen Media Research said yesterday.

The numbers were all the more impressive because it was a Friday night in August, when many people have better things to do than watch TV.

The most recent summer Olympics, in Athens four years ago, averaged 25.4 million viewers for its first night, Nielsen said. Sydney in 2000 had 27.3 million viewers.

NBCOlympics.com registered 70 million page views on Friday, its heaviest traffic ever.

IOC bans sprinter.

Greek sprinter Katerina Thanou has been barred from the Beijing Olympics for her role in a drug-testing scandal at the Athens Games four years ago.

The International Olympic Committee announced the ban today after it investigated Thanou's selection for the 100 meters for the Greek team.

Thanou and fellow Greek sprinter Kostas Kenteris missed doping tests on the eve of the 2004 opening ceremonies, claiming they were hurt in a motorcycle accident.

Scalpers beware.

There may be swarms of security volunteers and police officers posted every 100 feet along Beijing's main roads, but scalpers are still managing to find unguarded pieces of sidewalk to tout the hottest tickets in town.

The police have told Chinese reporters that ticket scalpers can be detained for 10 to 15 days, but also raised the threat of reeducation camps, where Chinese can be sentenced to manual labor without trial. Amnesty International and other human- rights groups have asked China to eliminate the practice.

Tennis withdrawals.

Ivo Karlovic of Croatia withdrew from the Olympics because of a stomach illness, less than two weeks after his upset of top-ranked Roger Federer at the Cincinnati Masters.

Fellow Croatian Ivan Ljubicic also pulled out of singles due to back trouble. He still plans to play doubles in the tournament, which begins today.

Tatiana Golovin of France, hampered by a back injury, withdrew from singles and doubles today shortly before the scheduled start of the tournament.