Introduction: Academic stress may cause the changes in the physical and mental activity of students so that aim of the present study was to correlate effect of academic stress and Physical Activity with Respiratory exchange ratio. and creating awareness about physical activity and life style modification for primary prevention of cardiovascular and metabolic and mental disorders. Methodology: This observational study conducted in Department of Physiology, RUHS College of Medical Sciences after taking approval from the ethical committee. A total 70 subjects screened out of 40 subject had stress score greater than 20 were included, aged 18-25 years both sexes male and female included. Data collection procedure & instrument used were Medical Stress Scale, Globalphysicalactivityquestionnaire, Resting exchange ratio assessed. Results: The BMI was positively correlated with RER and stress score and negatively correlated with physical activity and RER negatively correlated with physical activity and positively correlated with stress score physical activity negatively correlated with stress score. Conclusion: The utility of physical activity used as a one of strategy for coping or stress management and prevention of activation of various inflammatory pathways leading to development of various cardiovascular, metabolic and mental disorders.