What is a negative effect of smoking on physical fitness?

Smoking negatively impacts physical fitness by decreasing endurance. The harmful substances in tobacco smoke reduce the efficiency of the lungs in delivering oxygen to the bloodstream, which is crucial for aerobic activities. When lung function is compromised, the body's ability to perform sustained physical activity diminishes, leading to increased fatigue and reduced stamina. This makes it more challenging for individuals to engage in exercise or athletic performance, as endurance is a key component of physical fitness.

The other options suggest benefits that are contrary to the established effects of smoking; for instance, smoking does not increase lung capacity, improve heart health, or enhance athletic performance. Instead, it has been shown to cause significant detriments to cardiovascular health, lung function, and overall physical capabilities.