A longitudinal study to COVID-19 infection among university students: Physical fitness changes and psychological responses.

Background: The impact of COVID-19 infection on physical and mental health of young adults remains unclear. This study aimed to investigate the changes in the physical fitness three months after recovering from acute COVID-19 infection, and examine if the infection could also influence the mental health of university students.

Methods: A total of 460 university students (mean age 18.9 ± 1.3 years, with 30 males and 27 females uninfected with COVID-19) volunteered for the study. Participants underwent a fitness test initially, followed by another physical fitness test and a mental health assessment three months after the infection of COVID-19. Physical fitness tests included body composition, flexibility, cardiorespiratory fitness, muscle strength, and muscular endurance. Mental health was assessed using the Depression-Anxiety-Stress Self-Assessment Scale (DASS-21), the Pittsburgh Sleep Quality Inventory (PSQI), and the Post-Traumatic Stress Disorder Self-Assessment Scale (PTSD).

Results: Three months after acute COVID-19 infection, the physical performance of university students had decreased compared to pre-infection levels by approximate 3-15 % ( < 0.05). Regarding mental health, a notable difference was observed in sleep quality, with the positive group scoring 19 % higher than the negative group ( < .05,  = .44). Sex ( = .164,  < .05), previous infection ( = .277,  = .019) and anxiety ( = .373,  = .002) were predictive of PSQI scores, accounting for 37.5 % of the variance.

Conclusions: All participants experienced a decline in physical fitness compared to their pre-infection levels, regardless of infection status. Those who had been infected exhibited poorer sleep quality compared to their non-infected peers. Prior COVID-19 infection and higher anxiety levels may contribute to poorer sleep quality.