Iris started smoking in Paris, France at age 17 so that she too could look "cool," like her smoking friends and like Rhonda. Little did Iris realize that being "cool" meant no more running. Tars and carbon monoxide quickly rob the body of up to 30% of its breathing capacity. Imagine never again being able to engage in prolonged vigorous physical activity. The heart and muscles need extra oxygen for vigorous exercise. But smoking fills Iris's bloodstream with carbon monoxide and half of the carbon monoxide she inhales is still circulating in her bloodstream four hours later.