Author(s): HONGJUN, Y., LIN, S., YANG, Q., Institution: TSINGHUA UNIVERSITY, Country: CHINA, Abstract-ID: 1533

INTRODUCTION:
Psychological distress is increasingly prevalent among university students worldwide. Although physical activity has been widely studied, less attention has been given to objectively measured physical fitness components-particularly muscular fitness. This study examined associations between multiple physical fitness indicators and psychological distress in Chinese male university students.
METHODS:
A cross-sectional study was conducted among 3,102 male university students (mean age 19.14 ± 1.19 years) from Tsinghua University. Psychological distress was assessed using the 12-item General Health Questionnaire (GHQ-12), with 26.9% classified as distressed. Physical fitness was evaluated using standardized national testing protocols administered via the Tsinghua Tongfang S5000 Physical Fitness Testing System. Indicators included vital capacity (cardiorespiratory fitness), standing long jump (lower-body muscular power), and pull-ups (upper-body muscular endurance). Binary logistic regression models were applied to examine associations between fitness components and psychological distress, adjusting for age and academic grade.
RESULTS:
The overall mean vital capacity was 4263 ± 685 mL, standing long jump distance was 223.7 ± 22.9 cm, and pull-up performance was 7.61 ± 7.21 repetitions. Students classified as psychologically distressed demonstrated consistently poorer performance across all fitness components compared with non-distressed peers. In adjusted binary logistic regression models, lower pull-up performance showed the strongest association with psychological distress (OR = 1.17, 95% CI: 1.10-1.24, p < 0.001). Standing long jump performance was similarly associated with increased distress risk (OR = 1.15, 95% CI: 1.08-1.22, p < 0.001), as was reduced vital capacity (OR = 1.16, 95% CI: 1.09-1.23, p < 0.001). A clear graded relationship was observed, with progressively higher odds of psychological distress across declining fitness levels, supporting a dose–response pattern independent of confounding factors.
CONCLUSION:
Muscular endurance, muscular power, and cardiorespiratory fitness were independently and dose-dependently associated with psychological distress in male university students. Notably, muscular fitness demonstrated the strongest association, highlighting its potential importance in mental health beyond traditional weight-based indicators. These findings suggest that interventions targeting improvements in muscular and cardiorespiratory fitness may contribute to psychological health promotion in young adult males.