This study aims to investigate the relational model between physical activity, mental health (stress, anxiety, and depression), body mass index (BMI), and sleep quality among university students under crisis conditions—specifically, the combined military threats and media warfare experienced in Iran. This descriptive-correlational research will target students studying at Tehran universities. A sample of 202 participants (determined via G-Power software) will be recruited through convenience sampling. Data will be collected online using the International Physical Activity Questionnaire (IPAQ), the Depression, Anxiety, and Stress Scale (DASS-21), and the Pittsburgh Sleep Quality Index (PSQI). Given the unique context—including air-raid threats, psychological warfare, university closures, and increased sedentary behavior—this study seeks to identify the multifaceted interrelationships and predictive pathways among these variables. Its novelty lies in simultaneously examining these interactions within a real-world crisis setting, moving beyond previous research that has primarily focused on post-traumatic stress or direct physical injury. The findings are expected to provide evidence-based warnings and actionable insights for post-conflict intervention strategies and health policy-making, helping to safeguard the physical and mental well-being of the student population in the aftermath of the crisis.