Increasing the relative allocation of daily time to moderate-to-vigorous physical activity at the expense of sedentary behaviour is associated with modestly more favourable mental and perceived health in university students.
Key Findings
Results
A higher relative proportion of MVPA in the daily movement composition was associated with lower depressive symptoms and higher self-rated health in university students.
Sample included 2636 university students enrolled at the University of Milan, Italy, via anonymous web-based survey.
MVPA was associated with lower depressive symptoms (β = -0.39, 95% CI: -0.53 to -0.24) in adjusted compositional regression models.
MVPA was associated with higher self-rated health (β = 0.11, 95% CI: 0.08-0.13).
Physical activity was measured using the International Physical Activity Questionnaire (IPAQ) and analysed as a three-part composition (MVPA, LPA, SB) using compositional data analysis (CoDA).
Results
A higher relative proportion of sedentary behaviour in the daily movement composition was associated with higher depressive symptoms and lower self-rated health.
Sedentary behaviour was associated with higher depressive symptoms (β = 0.42, 95% CI: 0.21-0.64) in adjusted compositional regression models.
Sedentary behaviour was associated with lower self-rated health (β = -0.11, 95% CI: -0.14 to -0.07).
Depressive symptoms were measured using the Patient Health Questionnaire-9 (PHQ-9).
Results
Light physical activity (LPA) was not significantly associated with any of the mental health or self-rated health outcomes.
LPA was included as a component of the three-part daily movement composition alongside MVPA and sedentary behaviour.
No statistically significant associations were found between the relative proportion of LPA and PHQ-9 scores, self-rated health, or SCOFF scores.
This finding distinguishes LPA from both MVPA and sedentary behaviour in terms of their associations with the outcomes examined.
Results
Isotemporal substitution of 15 minutes from sedentary behaviour to MVPA was associated with lower depressive symptom scores, higher self-rated health, and higher eating disorder symptomatology scores.
Reallocating 15 minutes from sedentary behaviour to MVPA was associated with a PHQ-9 score reduction of -0.114 (95% CI: -0.156 to -0.072).
The same reallocation was associated with higher self-rated health (β = 0.031, 95% CI: 0.024-0.038).
The reallocation was also associated with a higher SCOFF score (β = 0.04, 95% CI: 0.00-0.07), indicating a modest increase in eating disorder-related symptomatology.
Isotemporal substitution modelling was used to estimate the theoretical effect of reallocating time between movement behaviours while keeping total waking time constant.
Methods
The study used compositional data analysis (CoDA) to examine waking movement behaviour, treating MVPA, LPA, and sedentary behaviour as a three-part composition rather than as independent variables.
CoDA and isotemporal substitution modelling were applied to account for the compositional and time-constrained nature of daily movement behaviours.
Outcomes included depressive symptoms (PHQ-9), self-rated health (SRH), and eating disorder-related symptomatology (SCOFF score).
Data were collected through a cross-sectional, anonymous web-based survey design, which limits causal inference.
The analytical sample included 2636 participants enrolled at the University of Milan, Italy.
What This Means
This research suggests that how university students divide their waking hours among physical activity and sitting is linked to their mental health and overall sense of wellbeing. Specifically, students who spent a greater share of their day doing moderate-to-vigorous physical activity (like brisk walking, jogging, or sports) reported fewer symptoms of depression and rated their own health more positively, while students who spent a greater share of their day being sedentary showed the opposite pattern. Simply doing light activity (such as slow walking or casual movement) was not linked to better or worse outcomes.
Using a statistical approach called isotemporal substitution, the researchers estimated what might happen if students theoretically shifted just 15 minutes from sitting to moderate-to-vigorous activity. This small reallocation of time was associated with modestly lower depression scores and slightly better self-rated health. Interestingly, it was also associated with a small increase in eating disorder-related symptom scores, a finding that warrants further investigation. The researchers note that these associations are modest in size and that the study design cannot prove causation.
This research suggests that promoting active lifestyles among university students — even through relatively small increases in time spent doing moderate-to-vigorous activity in exchange for less sitting — could be relevant for mental health and perceived wellbeing on university campuses. The findings highlight the potential value of public health efforts targeting sedentary behaviour specifically, rather than focusing only on overall physical activity levels, in this population.
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Pennisi F, Pinto A, Colizzi M, Signorelli C, Cozza A, Baldo V, et al.. (2026). Physical Activity, Sedentary Behaviour and Mental Health in University Students: A Compositional Isotemporal Substitution Analysis.. Depression and anxiety. https://doi.org/10.1155/da/4091641