Smokers not only suffer from nicotine addiction but the ravaging effects of thousands of inhaled chemicals upon their respiratory system and body. What was it like to run like the wind, to engage in an extended period of brisk physical activity without becoming seriously winded? What was it like to climb flight after flight of stairs, to play full-court basketball, or chase a child or the family pet without ending up gasping for air? Every now and then I meet a smoker who lets me know that they enjoy running. What they don’t seem to appreciate is the tremendous strain they subject their heart and body to when doing so. It’s a matter of availability of sufficient oxygen to keep vigorously working muscle well fueled and alive. Carbon monoxide is a colorless, odorless toxic gas produced when any carbon-based material is burned, including tobacco. When smoking, the amount of carbon monoxide entering the bloodstream varies greatly (up to 25mg per cigarette) depending upon such factors as how intensely the smoker smokes, whether or not they cover the filter ventilation holes with their lips, and the particular brand smoked.