The effects of smoking on fitness levels are profoundly negative, impairing lung function and cardiovascular health. Smoking reduces oxygen delivery to muscles, leading to decreased endurance and increased fatigue during physical activities. It also contributes to a higher risk of injuries and slower recovery times. Smokers often experience reduced exercise capacity, with diminished overall health, making it challenging to maintain an active lifestyle. Quitting smoking can significantly improve fitness levels and overall health, and encourage individuals to engage more actively in physical activities.