Smoking takes away all the benefits you seek from running in the first place: better circulation, improved lung capacity, greater endurance and, um, longer life. And while running may mitigate some of the effects of smoking, quitting is still the single best thing anyone who does smoke can do for their health in general, and their running in particular.
In the end, it's all about oxygen, and even a small amount of smoking can significantly degrade your performance as an athlete.
Read More: 10 Ways To Quit Smoking Now
The greater the amount of oxygen your body can procure, the faster and longer you'll be able to run. Smoke damages the lung's natural defenses, such as the epithelial cell barrier, which is responsible for both producing and clearing mucus.
For starters, that makes your lungs more vulnerable to infection. Tobacco smoke also exposes the tiny air sacs that allow the lungs to absorb oxygen and emit carbon dioxide -- known as the alveoli -- to damage from oxidative stress. The result: Reduced VO2 max, which is the amount of oxygen your body can use per minute, leading to poorer performance, less stamina and diminished endurance.
Don't Let Carbon Monoxide Choke You Out
Smoking reduces the volume of oxygen your blood can carry because your blood's hemoglobin binds 300 times more easily with carbon monoxide than it does with oxygen. If you think of your blood as a train that's supposed to transport oxygen to your tissues, then carbon monoxide is like a huge gang of unwanted tourists taking up all the seats.
That means oxygen gets crowded out. And it's not just a matter of not smoking before you run. In fact, smoking a cigarette alters oxygen transport for as long as 24 hours because nicotine constricts the blood vessels in the lungs. Two cigarettes a day are enough to adversely affect your performance.
Smoking puts you at a huge risk for coronary heart disease by contributing to plaque, which accumulates in the coronary arteries. Over time, plaque causes the arteries to narrow, reducing the flow of blood to the heart muscle. The presence of plaque also puts you at risk for blood clots forming in your arteries -- the arteries that supply the heart with oxygenated blood. The build-up of plaque in the arteries is called atherosclerosis.
As the coronary arteries become narrower, the flow of oxygen-rich blood to your muscles and other tissues diminishes. Neither a stroke nor a heart attack will do your running game much good, but before it even gets to that point, your stamina will be severely compromised. And ultimately, nerve damage to your extremities could make walking difficult and running impossible.
Now is the Time
The good news is that the lungs regenerate rapidly. Even a newly-minted non-smoker is likely to see the benefits of abstinence almost immediately. Within a month, your VO2 max should improve, along with your circulation, blood pressure and overall performance.
Read More: How to Keep the Respiratory System Healthy