Smoking reduces the respiratory system's ability to provide oxygen to working muscles. Smoking forces the heart and lungs to work harder and increases your blood pressure. The carbon monoxide from smoking lowers the blood's oxygen carrying capacity, and less oxygen means less energy for you. If you are a smoker, your body needs more oxygen, but uses it less efficiently. This leads to shortness of breath. Smokers have an increased risk of heart attack and stroke. As a result, it is recommended that you see a medical professional before starting an exercise program to determine if any exercises might be potentially harmful. However, exercise can be a motivator to quit smoking and to resist the temptation to start again. Since both exercising and quitting smoking are healthy activities, success in one area can motivate success in the other. Exercise can reduce the stress and burn off the excess energy that quitting may produce. It also distracts you and occupies your time. Instead of smoking, you can take a walk or swim. Exercise also helps control the snacking and weight gain that are usually associated with quitting smoking. For more information on smoking and exercise, contact a health care professional.