Associations of physical fitness with sleep quality and anxiety Among university students: a cross-sectional regression analysis

Background: Poor sleep quality and anxiety are prevalent among university students and pose growing public health concerns. Physical fitness is often assumed to be associated with better sleep and mental health outcomes; however, evidence based on objectively measured physical fitness in non-clinical student populations remains limited and inconsistent. Objective: This study aimed to examine the associations between multiple objectively assessed physical fitness components and sleep quality as well as anxiety outcomes among undergraduate students. Methods: A total of 50 undergraduate students (mean age: 20.3 ± 1.1 years; 26 males, 24 females) enrolled in general physical education courses participated in this cross-sectional study. Physical fitness was assessed using standardized tests, including vital capacity, 50-m sprint, standing long jump, and sit-and-reach. Sleep quality was evaluated using the Pittsburgh Sleep Quality Index (PSQI), and anxiety symptoms were assessed using the anxiety subscale of the Hospital Anxiety and Depression Scale (HADS-A). Outcomes were analyzed as both continuous scores and categorical risk indicators (sleep disturbance: PSQI > 5; elevated anxiety: HADS-A ≥ 8). Multivariable linear and binary logistic regression analyses were performed, adjusting for age and sex. Results: > 0.05). These null findings were consistent across different fitness domains and analytical approaches. Conclusions: Objectively measured physical fitness was not significantly associated with sleep quality or anxiety outcomes among non-clinical undergraduate students. These findings suggest that general physical fitness alone may have limited explanatory value for sleep and anxiety in university populations and highlight the importance of considering broader psychosocial and behavioral factors when addressing student mental health.