Acute effects of high intensity interval training on cognitive function in smokers and nonsmokers

The use of tobacco is widespread among both active and inactive individuals. However, its adverse effects appear less pronounced in those who exercise regularly. Since smoking may differentially impact smokers and nonsmokers, this study examined the immediate effect of high-intensity interval training (HIIT) on cognitive performance in both groups. Forty inactive participants (20 smokers, 20 nonsmokers) were included, with mean ages of 20.35±1.26 and 20.15±1.38 years, respectively. The HIIT protocol involved five exercises. Cognitive performance was assessed immediately after the session using the Visual Cognitive Function Test (VCFT) and Auditory Cognitive Function Test (ACFT), each repeated five times, with results recorded in milliseconds. Pre-test VCFT scores were significantly higher in smokers (381.16±7.96 ms) compared to nonsmokers (372.24±11.17 ms, p=0.006). Post-test scores also differed (smokers: 607.50±43.33 ms; nonsmokers: 577.66±20.78 ms, p=0.007). The improvement from pre- to post-test was greater in nonsmokers (-48.39 ms, p < 0.001) than in smokers (-25.39 ms, p=0.021). In ACFT, no significant group differences were found at pre-test (p=0.080) or post-test (p=0.079), but both groups showed significant improvement following HIIT (p<0.001). These results suggest that smoking impairs visual cognitive performance more than auditory function after high-intensity exercise. The differences may stem from smoking-related vascular and neural plasticity deficits, which are critical for cognitive processing during and after exercise. Significance statement: This study highlights that smoking specifically reduces visual cognitive benefits from HIIT, while auditory function remains less affected. These findings emphasize the neurobiological consequences of smoking and support the role of exercise interventions in mitigating its adverse cognitive effects.