Smoking negatively impacts physical endurance and lung health by damaging the respiratory system and reducing lung capacity. The inhalation of harmful substances leads to inflammation, decreased oxygen exchange, and diminished performance during physical activities. Smokers often experience shorter endurance during activities, increased breathlessness, and overall reduced exercise capacity. These effects can hinder fitness goals and contribute to chronic respiratory conditions like chronic obstructive pulmonary disease (COPD), further diminishing quality of life and increasing the risk of complications related to physical inactivity.