It's not 100% good for the body because you're inhale more exhaust gas. By the way let's not forget that the US cyclists wear masks at the Beijing 2008 Olympiad

It's not 100% good for the body because you're inhale more exhaust gas. By the way let's not forget that the US cyclists wear masks at the Beijing 2008 Olympiad [1]. [1] http://www.nytimes.com/2008/08/06/sports/olympics/06masks.html http://www.nytimes.com/2008/08/06/sports/olympics/06masks.ht...