Author(s): BRAUN, B., CURTISS, J., NORTHEY, J., HILLMAN, C., RAINE, L., Institution: NORTHEASTERN UNIVERSITY , Country: UNITED STATES, Abstract-ID: 1250

Introduction
Stress and anxiety are increasingly prevalent among college students, with significant implications for mental health and academic performance. Identifying physical health factors that mitigate the impact of stress on anxiety is critical for developing targeted interventions. Previous research suggests that physical fitness and body composition may independently influence mental health [1,2]. Cardiorespiratory fitness (CRF) is typically expressed relative to total mass, but it is directly related to fat-free mass. Thus, fat-free CRF (FF CRF) may provide a more direct measure of oxygen delivery, as fat mass may be related to oxygen delivery dysfunction. Therefore, this study examined whether CRF (relative to both total mass and fat-free mass), lean mass (LM), and fat mass (FM) moderate the relationship between perceived stress and self-reported anxiety.
Methods
Participants (N=135; 80 females; ages 18–25 years) completed a maximal exercise (VO₂max) test to assess CRF, a dual-energy X-ray absorptiometry scan to quantify LM and FM (adjusted for total mass), and self-report measures of stress (Perceived Stress Scale) and anxiety (State-Trait Anxiety Inventory). FF CRF was computed as VO₂max relative to fat-free mass. Predictor and moderator variables were mean-centered, and linear regression models were conducted after controlling for age and sex. Interaction terms were included to test the moderating effects of CRF, FF CRF, LM, and FM individually on the stress-anxiety relationship.
Results
Perceived stress significantly predicted anxiety (B=1.10 , p<.001). CRF moderated this relationship (B= -0.024, t(117)=-2.49, p=.014), such that as CRF increased, the relationship between stress and anxiety decreased. Interestingly, FF CRF did not show a moderation effect (B=-0.021, t(116)=-1.90, p=.059). However, LM moderated the stress-anxiety association (B=-2.364, t(122)=-2.32, p=.022), indicating that for individuals with greater LM the relationship between stress and anxiety was weaker. Conversely, increased FM amplified the stress-anxiety relationship (B=2.299, t(122)=2.32, p=.022), suggesting that higher fat mass may increase vulnerability to stress-induced anxiety. Models explained 60.0-61.6% of variance in anxiety (R²=.600–.616).
Conclusion
Our findings highlight the differential roles of CRF, LM, and FM in the stress-anxiety relationship. These results underscore the importance of integrating fitness and body composition into interventions aimed at reducing stress and anxiety in young adults.
References
[1] Torres, L., et al. (2023). Correlations between Mental Health, Physical Activity, and Body Composition in American College Students after the COVID-19 Pandemic Lockdown. International Journal of Environmental Research and Public Health, 20(22).
[2] Wiklund, C. A., Let al. (2024). Change in Cardiorespiratory Fitness and Risk of Depression, Anxiety, and Cerebrovascular Disease. American Journal of Preventive Medicine, 67(6).