The impact of smoking on fitness and health is profound, as it adversely affects lung capacity, circulation, and overall endurance. Smoking introduces harmful toxins that impair oxygen transport, leading to reduced performance in physical activities. Furthermore, it can contribute to chronic illnesses such as heart disease and lung cancer, limiting one’s ability to engage in even moderate exercise. Quitting smoking can lead to significant improvements in fitness levels and overall health, enhancing longevity and quality of life.