The aim of the current study was to examine the associations between physical activity, mobile phone addiction, and irrational procrastination after adjustment for potential confounding variables. The participants were 6294 first- and second-year students recruited as a cluster sample from three public universities in Shanghai, China. Physical activity, mobile phone use, and irrational procrastination were assessed using the International Physical Activity Questionnaire-Short Form (IPAQ-SF), the mobile phone addiction index scale (MPAI), and the irrational procrastination scale (IPS). The participants were divided into four groups according to their mobile phone usage status and physical activity level. The binary logistic regression model was used to predict the probability of serious irrational procrastination among different groups. The emergence of serious of irrational procrastination under physical activity of different intensity and different mobile phone addiction statuses was predicted by a multiple linear regression model. In this study, the combination of insufficient physical activity and mobile phone addiction is positively associated with high levels of irrational procrastination. Furthermore, students who exhibited both mobile phone addiction behaviors and insufficient physical activity tended to have significantly higher odds of reporting high levels of irrational procrastination than those students who exhibited one behavior or neither behavior. After adjusting for the effects of age, BMI, tobacco, alcohol use, and sedentary time, the result is consistent with previous outcomes. These findings suggest that intervention efforts should focus on the promotion of physical activity and reduction of mobile phone addiction.

Background: While physical activity has been reported to positively affect stress and sleep quality, less is known about the potential relationships among them. The present study aimed to investigate the mediating effect of stress on the association between physical activity and sleep quality in Chinese college students, after controlling for age, nationality, and tobacco and alcohol use. Participants: The sample comprised 6973 college students representing three Chinese universities. Methods: Physical activity, perceived stress, and sleep quality were respectively measured using the International Physical Activity Questionnaire—Short Form (IPAQ-SF), Perceived Stress Scale—10 Items (PSS-10), and Pittsburgh Sleep Quality Index (PSQI). Results: Mediating effects of perceived stress on the association between physical activity and sleep quality were observed in males and females, with 42.4% (partial mediating effect) and 306.3% (complete mediating effect) as percentages of mediation, respectively. Conclusion: The results of this study may provide some suggestions that physical activity could improve sleep by aiding individuals in coping with stress and indicate that stress management might be an effective non-pharmaceutical therapy for sleep improvement.

Objective: The present study aimed to examine the relationship between physical fitness and academic performance, after controlling for potential confounds. Participants: The sample comprised 2,324 college students representing three Chinese universities. Methods: Physical fitness was measured using the Chinese National Student Physical Fitness Standard; academic performance (ie, Grade Point Average) and lifestyle behaviors were assessed using questionnaires. Academic performance and overall physical fitness were used to divide participants into three categories: low, moderate, and high. Results: Several physical fitness indicators systematically differed across the three academic performance categories. Additionally, overall physical fitness was positively associated with academic performance, even after controlling for the effects of lifestyle behaviors; those who belonged to the high overall physical fitness group had lower odds ratios of low academic performance than those belonging to the low overall physical fitness group. Conclusions: Poor academic performance was related to low overall physical fitness . The probability of having poor academic performance was significantly lower among students with high physical fitness than those with low physical fitness.

The negative impact of COVID-19 on physical activity has been improved, while the research on changes in physical fitness that may be caused by physical inactivity is still scarce. This study aims to explore the impact of the COVID-19 pandemic lockdown on physical fitness, and the impact of initial physical fitness indicators on their changes during the lockdown in adolescents. A longitudinal study including 265 adolescents aged 14.1 ± 0.4 years old was conducted in China. Physical fitness measurement at baseline and follow-up were respectively measured before (November 2019) and after the lockdown (July 2020). Several physical fitness indicators including aerobic fitness (i.e., 800-m or 1000-m run) and explosive force (i.e., 50-m sprint) deteriorated during the lockdown. Whereas the performances of vital capacity, flexibility (i.e., sit and reach), and muscular strength (i.e., pull-ups) were significantly improved during the lockdown. Furthermore, the reduction in physical fitness for adolescents with higher physical fitness before the lockdown was greater than that for others. These findings may contribute to the development of targeted intervention strategies for physical fitness promotion during the lockdown caused by the public health emergency.

Background and objectives: Existing studies concerning the associations of cognitive function with adiposity in young adults are sparse. The purpose of the study was to examine the associations of adiposity with cognitive control in young adults. Materials and Methods: Participants were 213 young adults (98 women and 115 men). Cognitive control was measured using a modified task-switching paradigm. Anthropometrics were measured by standardized procedures. Body fat mass and visceral fat area were measured by bioelectrical impedance analysis. Results: The results showed that increased body mass index (BMI, p = 0.02), body fat percentage (p = 0.02), and visceral fat area (p = 0.01) were significantly correlated with larger global switch costs of accuracy in women. In men, high levels of body fat percentage (p = 0.01) and visceral fat area (p = 0.03) were significantly correlated with larger local switch costs of reaction time. Conclusions: The results indicated that elevated adiposity was associated with worse performance on measures of cognitive control in young adults.

Purpose: Premenstrual syndrome refers to a set of distressing symptoms experienced before the menstrual flow, which can affect female students’ behavior, cognitive abilities, mental health status, and academic performance. Identifying modifiable risk factors is essential to reduce the prevalence college students’ premenstrual syndrome. We examined associations between premenstrual syndrome and physical activity and sedentary behavior in Chinese female college students.Methods: In this cross-sectional study, 315 female college students volunteered to participate at a university in Shanghai, China. We measured physical activity and sedentary behavior using the ActiGraph GT3X-BT and assessed premenstrual syndrome using the Premenstrual Symptoms Screening Tool. The data were statistically analyzed using SPSS 24.0 software, and the primary analysis methods included Kruskal-Wallis test and logistic regression analysis.Results: Among the 221 female college students who met the inclusion criteria, 148 (67.0%) had PMS while 73 (33.3%) did not. After controlling for confounding variables, moderate physical activity and moderate to vigorous intensity physical activity were significantly associated with premenstrual syndrome. There was no correlation between light-intensity physical activity, sedentary behavior, and premenstrual syndrome in the study.Conclusion: Premenstrual syndrome is prevalent among Chinese female college students. Moderate physical activity and moderate-to-vigorous physical activity can be effective in reducing PMS symptoms.