An analysis of the role of college students' core self-evaluation in the relationship between extracurricular physical exercise and academic stress.

Objective: To explore the role of college students' core self-evaluation in the association between extracurricular physical exercise and academic stress, and to provide a reference and basis for effectively alleviating current college students' academic stress. Methods: A stratified cluster random sampling method was used to conduct an online survey using the China College Student Mental Health Screening Scale, the Core Self-Esteem Scale, and a self-developed questionnaire for 1,249 college students from 8 junior colleges in Jiangsu Province, China, in January 2023, and analyses were conducted using bivariate correlation and mediation effect tests. Results: More than half of the students were worried about lagging behind other students in their studies and worrying about exams, as well as more than half of the students had <2 h of extracurricular physical exercise per week in terms of academic stress. Significant correlations were found between extracurricular physical exercise time and core self-evaluation (r = 0.225, p < 0.01), academic stress (r = -0.317, p < 0.01), and between core self-evaluation and academic stress (r =-0.371, p < 0.01). Extracurricular physical exercise had a negative predictive effect on academic stress (effect = -0.306, 95%CI: -0.361~-0.251) and partially through the mediating path of core self-evaluation, (effect = -0.067, 95%CI: -0.091~-0.046), with a mediating effect of 21.9%. Among them, the mediating effect of core self-evaluation was highest in "worrying about lagging behind other students in their studies" and "worrying about exams", which accounted for 24.4% and 24.3% respectively. Conclusion: Currently, college students have different degrees of academic stress; extracurricular physical exercise can reduce academic stress through direct effects, and also through the indirect effect of improving the level of core self-evaluation, and active extracurricular physical exercise has become an important way to promote students' physical and mental health.

The impact of physical activity on electronic media use among chinese adolescents and urban-rural differences.

OBJECTIVE: With the prevalence of electronic media use among Chinese adolescents and concerns regarding its potential negative consequences on their health and development, this study investigated the relationship between physical exercise and electronic media use. Utilizing data from the China Education Panel Survey, we examine the impact of physical activity on adolescents' electronic media use. METHODS: A simultaneous equation model, including two-stage least square and three-stage least square, was employed to estimate the impact of physical activity on electronic media use among adolescents. Self-control theory and media addiction theory were also used to analyze electronic media use in adolescents. Descriptive statistics were used to analyzed the data. RESULTS: Chinese adolescents dedicated a substantial amount of time, averaging 2.95 hours per day, to electronic media activities. Increasing physical activity demonstrated an effective means to reduce electronic media use. Furthermore, the impact of physical activity on electronic media use exhibited urban-rural stratification, with family factors related to social class status primarily influencing electronic media use among urban students, while physical activity has a more pronounced influence among rural students. CONCLUSIONS: Promoting physical activity represents a compelling and effective strategy for curbing excessive electronic media use among Chinese adolescents, particularly in rural areas where physical activity has a stronger influence. In addition, controlling media entertainment and recreation time and enhancing social cohesion can help to weaken media interest. While changing the social class status of families in urban areas may be difficult in the short term, parents should be aware that physical exercise is an effective way to reduce their children's use of electronic media. Our findings suggested that promoting physical activity may be a promising strategy for reducing excessive electronic media use among Chinese adolescents, particularly in rural areas where physical activity has a stronger influence.

Downhill Running Acutely Elicits Mitophagy in Rat Soleus Muscle.

PURPOSE: This study aimed to investigate the effects of downhill treadmill running on mitochondrial structure/function and expression levels of mitophagy-related proteins in rat skeletal muscle. METHODS: A total of 48 male adult Sprague-Dawley rats were randomly divided into a control group (C, n = 8) and an exercise group (E, n = 40). Rats in the E group were exercised on a treadmill down a 16° decline at 16 m·min for 90 min and were further divided into 0 h (E0), 12 h (E12), 24 h (E24), 48 h (E48), and 72 h (E72) postexercise subgroups (n = 8 each). At each time point, the soleus muscle was collected under full anesthesia. Mitochondrial ultrastructural changes in skeletal muscle were observed by a transmission electron microscope. The content of quantitative enzyme citrate synthase and the activities of mitochondrial respiratory chain complex II and complex IV were measured by enzyme-linked immunosorbent assay. Protein expressions of skeletal muscle cytochrome c oxidase subunit 1 (COX1), PTEN-induced putative kinase 1 (PINK1), and mitochondrial Parkin microtubule-associated protein 1 light chain 3 (LC3) were determined by Western blot. Mitochondrial colocalizations with Parkin, ubiquitin (Ub), p62/sequestosome 1 (p62), and LC3 were measured by the immunofluorescence double labeling technique. RESULTS: After downhill treadmill running, the skeletal muscle mitochondrial structure changed dramatically, and a large amount of mitophagosomes were observed; the citrate synthase content and complex II activity were significantly lower (P < 0.05), whereas complex IV activity and COX1 protein level remained unchanged; the expression levels of PINK1, Parkin, Ub, p62, and LC3 were significantly higher than those in the C group (P < 0.05 or P < 0.01). CONCLUSION: A session of downhill treadmill running activated the PINK1/Parkin pathway and facilitated mitochondrial colocalizations with Ub, p62, and LC3, causing mitophagy and mitochondrial damage within the skeletal muscle.