The effect of replacing sedentary behavior with different intensities of physical activity on depression and anxiety in Chinese university students: an isotemporal substitution model.

BACKGROUND: Previous research has suggested that engaging in regular physical activity (PA) can help to reduce symptoms of depression and anxiety in university students. However, there is a lack of evidence regarding the impact of reducing sedentary behavior (SB) and increasing light-intensity PA (LPA) on these symptoms. This study aims to address this gap by using isotemporal substitution (IS) models to explore how substituting SB with LPA or moderate-to-vigorous PA (MVPA) affects depression and anxiety symptoms among university students. METHODS: The study recruited 318 university students with a mean age of 21.13 years. Accelerometers were used to objectively measure the time spent on SB, LPA, and MVPA, while depression and anxiety symptoms were assessed using the Center for Epidemiologic Studies Depression Scale (CES-D) and the Self-rating Anxiety Scale (SAS). IS models using multivariable linear regression were employed to estimate the associations between different behaviors and depression and anxiety symptoms when 30 min of one behavior was substituted with another. RESULTS: In the single-activity model, less SB (ß = 0.321, 95% CI: 0.089, 1.297) and more MVPA (ß = -0.142, 95% CI: -1.496, - 0.071) were found to be significantly and negatively associated with depression scores, while less SB (ß = 0.343, 95% CI: 0.057, 1.014), LPA (ß = 0.132, 95% CI: 0.049, 1.023), and more MVPA (ß = -0.077, 95% CI: -1.446, - 0.052) were significantly and negatively correlated with anxiety scores. The IS analysis revealed that substituting 30 min of SB with LPA (ß = -0.202, 95% CI: -1.371, - 0.146) or MVPA (ß = -0.308, 95% CI: -0.970, - 0.073) was associated with improvements in depressive symptoms. Substituting 30 min of SB with MVPA (ß = -0.147, 95% CI: -1.863, - 0.034) was associated with reduced anxiety symptoms. CONCLUSION: Replacing 30 min of SB with MVPA may alleviate depression and anxiety symptoms in university students. Further research is needed to explore the long-term effects of PA interventions on the mental health disorders of this population.

The role of fundamental movement skills on children's physical activity during different segments of the school day.

BACKGROUND: Although prior studies have demonstrated that children with high levels of fundamental movement skill (FMS) are more active throughout the day, little is known about children's FMS and their physical activity (PA) during different segments of the school day (e.g., recess, lunch break, and physical education). The present study focused on FMS and moderate-to-vigorous PA (MVPA) during school day and identifies the association between children's FMS and MVPA during different segments of the school day in China. METHODS: A total of 322 children (boys n = 163, girls n = 159; Mage = 8.12, SD = 1.22 years) from four elementary schools involved in this study. Children's FMS and MVPA were measured using the Test of Gross Motor Development-2nd edition (TGMD-2) and hip-mounted accelerometers. Data such as height, weight, and socio-economic status (SES) were also obtained. Multilevel mixed regression models were used to examine the cross-sectional associations between FMS and MVPA. Models were adjusted for gender, age, standardized body mass index, and SES. RESULTS: Children engaged in 32.19 min of MVPA during the whole school day. Boys were more active than girls and had higher object-control skills competency. Locomotor skills were positively associated with children's long recess (B = 1.063) and short recess time (B = 1.502) MVPA. Object-control skills were positively correlated with children's MVPA time during long recess (B = 1.244) and physical education (PE) lessons (B = 1.171). CONCLUSION: The findings highlight the importance of developing both locomotor and object-control skills in elementary schools to lead more MVPA engagement during different segments of the school day.