Many critics often point to smoking as one of the most harmful habits for fitness and overall health. However, over the years, there has been a noticeable shift from smoking cigarettes to using chewing tobacco. This shift reflects a broader social rhythm: people tend to substitute one habit for another, even when it comes to their health and fitness routines. When it comes to athletic performance, the negative effects of smoking are widely understood—reduced lung capacity, decreased endurance, and slower recovery, among others. But what about chewing tobacco? How does it affect someone who is actively engaged in high-intensity workouts or competitive sports? In my observations as a certified personal trainer, I have noticed a significant number of individuals who regularly consume nicotine—through chewing tobacco or other forms—yet still participate in demanding physical activities. This raises the question: can nicotine impact running performance, strength training, or overall fitness? Based on my professional training experience and personal observations, nicotine can indeed influence athletic performance. While it may not have the same immediate effects on lung function as smoking, nicotine has a range of physiological impacts, including increased heart rate, elevated blood pressure, and potential interference with oxygen delivery to muscles. These factors can subtly limit endurance, reduce stamina, and affect recovery after workouts. Understanding the effects of nicotine on fitness is essential for anyone serious about reaching peak performance. As a certified personal trainer through the National Federation of Professional Trainers (certificate number 45582), I aim to provide insights based on both professional expertise and real-world experience, helping athletes and fitness enthusiasts make informed decisions about their habits and performance goals.