Yetersiz fiziksel aktivitenin yaygın olarak görülmesi, küresel bir halk sağlığı problemi olarak karşımıza çıkmaktadır. Yeterli düzey ve yoğunlukta yapılan düzenli fiziksel aktivitenin fiziksel ve ruhsal sağlık açısından yararları yadsınamamaktadır. Ancak

The widespread prevalence of inadequate physical activity is a global public health problem. The benefits of regular physical activity at adequate levels and intensity regarding physical and mental health cannot be denied. However, with the spread of sedentary life, the number of individuals who perform physical activity at a sufficient level is decreasing. One’s attitudes toward physical activity can affect how much they do it. These attitudes may also negatively affect problematic internet use by encouraging sedentary lifestyles. This study aims to investigate the relationship between psychological stress, internet addiction, and attitudes toward physical activity that affect the level of physical activity in medical students aged 18– 25 years. For this purpose, an online questionnaire was designed and distributed to participants via the internet. Sociodemographic Data Form, Young Internet Addiction Test-Short Form, Depression-AnxietyStress Scale-21, Cognitive Behavioral Physical Activity Questionnaire, and International Physical Activity Questionnaire-Short Form were used in the survey form. A total of 186 medical students, consisting of 105 females (56.5%) and 81 males (43.5%), participated in the study. Of the participants, 37 (19.9%) stated that they performed sufficient physical activity. Internet addiction scores did not predict physical activity, whereas personal barriers, self-regulation, and outcome expectancy among attitudes toward physical activity predicted adequate physical activity levels. In conclusion, the variable that best predicts physical activity level in medical students is attitudes toward physical activity. Regular physical activity is recommended for the protection of mental and physical health. In conclusion, attitudes toward physical activity emerged as the most significant predictor of physical activity levels among medical students.