Purpose <p>Tobacco consumption remains the primary preventable factor contributing to disease and mortality worldwide, representing a significant public health challenge. Notably, its prevalence is particularly high among athletes, including university athletes. This study investigates the impact of acute curcumin supplementation on oxidative stress markers after incremental exercise in active smokers and non-smokers, aiming to elucidate the potential protective effects of curcumin in this context.</p> Methods <p>In this randomized crossover study, 16 smokers and non-smokers active men randomly consumed either a 1000 mg curcumin capsule or a placebo (corn starch) capsule 2 h before exercise in two trials separated by a week washout period. Blood pressure (BP), heart rate (HR), and serum malondialdehyde (MDA), total antioxidant capacity (TAC), and superoxide dismutase (SOD) were measured at baseline and after performing the Bruce protocol on a treadmill.</p> Results <p>Maximal oxygen uptake and HR_mean of smokers were 16% and 12% lower than those of non-smokers, respectively. Systolic, but not diastolic BP, was similarly elevated after exercise in both groups, while pre- and post-exercise diastolic BP decreased in non-smokers with curcumin intake. Curcumin intake had no significant effect on post-exercise MDA, TAC, and SOD (<i>P</i> &gt; 0.05).</p> Conclusions <p>Smoking may reduce the aerobic capacity of university athletes, and smokers reach exhaustion at a lower heart rate. Acute high-dose curcumin intake may reduce post-exercise diastolic BP in non-smokers, but may not help to reduce oxidative stress following exercise. Smoker athletes are encouraged to quit smoking and follow a healthy lifestyle.</p>