That was fast. Four members of the U.S. Olympic cycling team have apologized for wearing face masks yesterday at the Beijing airport:

The wearing of protective masks upon our arrival into Beijing was strictly a precautionary measure we as athletes chose to take, and was in no way meant to serve as an environmental or political statement," the athletes said. "We deeply regret the nature of our choices. Our decision was not intended to insult BOCOG or countless others who have put forth a tremendous amount of effort to improve the air quality in Beijing."

The chairman of the U.S. Olympic Committee says the athletes wrote the letter of their own accord. About 200 members of the American team are thought to have brought masks to Beijing.

Of course, it's worth noting that plenty of Chinese cyclists wear face masks:

FREDERIC J. BROWN/AFP/Getty Images