<qa>  What is the most common risk factor for lung cancer?Cigarette smoking is the most common risk factor for lung cancer, and it increases the risk of developing other cancers, chronic lung disease, and heart disease. A smoking cessation program that incorporates physical activity may be beneficial in improving long-term smoking cessation rates. This study will evaluate the effectiveness of a community-based physical activity program, in combination with nicotine replacement therapy and a behavioral smoking cessation program, at improving cessation rates among sedentary smokers. 