Smoking adversely influences physical fitness by impairing lung function and reducing overall aerobic capacity. It decreases oxygen delivery to the muscles, making physical activities more challenging and less effective. Smokers may experience faster fatigue and longer recovery times. Additionally, smoking is linked to various health issues, including cardiovascular diseases and chronic obstructive pulmonary disease (COPD), which further hamper exercise performance and overall well-being. Quitting smoking can lead to significant improvements in fitness levels and quality of life.