(1) Background: The novel coronavirus disease 2019 (COVID-19) is a global public health emergency that has caused worldwide concern. Vast resources have been allocated to control the pandemic and treat patients. However, little attention has been paid to the adverse impact on mental health or effective mitigation strategies to improve mental health. (2) Purpose: The aim of this study was to assess the adverse impact of the COVID-19 outbreak on Chinese college students’ mental health, understand the underlying mechanisms, and explore feasible mitigation strategies. (3) Methods: During the peak time of the COVID-19 outbreak in China, we conducted longitudinal surveys of sixty-six college students. Structured questionnaires collected information on demographics, physical activity, negative emotions, sleep quality, and aggressiveness level. A mixed-effect model was used to evaluate associations between variables, and the mediating effect of sleep quality was further explored. A generalized additive model was used to determine the dose-response relationships between the COVID-19 death count, physical activity, and negative emotions. (4) Results: The COVID-19 death count showed a direct negative impact on general sleep quality (β = 1.37, 95% confidence interval [95% CI]: 0.55, 2.19) and reduced aggressiveness (β = −6.57, 95% CI: −12.78, −0.36). In contrast, the COVID-19 death count imposed not a direct but an indirect impact on general negative emotions (indirect effect (IE) = 0.81, p = 0.012), stress (IE = 0.40, p < 0.001), and anxiety (IE = 0.27, p = 0.004) with sleep quality as a mediator. Moreover, physical activity directly alleviated general negative emotions (β = −0.12, 95% CI: −0.22, −0.01), and the maximal mitigation effect occurred when weekly physical activity was about 2500 METs. (5) Conclusions: (a) The severity of the COVID-19 outbreak has an indirect effect on negative emotions by affecting sleep quality. (b) A possible mitigation strategy for improving mental health includes taking suitable amounts of daily physical activity and sleeping well. (c) The COVID-19 outbreak has reduced people’s aggressiveness, probably by making people realize the fragility and preciousness of life.

Although converging evidence has demonstrated that exposure to fine particulate matter (PM_2.5) caused adverse effects on brain structure and cognitive function, the association between the short-term exposure to PM_2.5 and cognition dysfunction remained underexplored, especially possible neurophysiological mechanisms. We conducted a longitudinal observational study with four repeated measurement sessions among 90 young adults from September 2020 to June 2021. During each measurement session, we measured participants' personal-level air pollution exposure for one week with portable monitors, followed by executive function assessment and electrophysiological signal recording at an assessment center. Standard Stroop color-word test was used accompanied with electroencephalogram (EEG) recording to assess performance on executive function. We used linear mixed-effect model with lagged values of PM_2.5 levels to analyze the association between PM_2.5 exposure and changes in executive function, and mediation analysis to investigate mediation effect by EEG signal. Adjusted mixed-effect models demonstrated that elevated PM_2.5 exposure three days prior to cognitive assessment (lag-3) was associated with (1) declined performance in both congruent and incongruent tasks in Stroop test, (2) reduced lower and upper alpha event-related desynchronization (ERD) during 500-1000 ms after stimuli, both indicating impaired executive control. Lower and upper alpha ERD also mediated observed associations between short-term PM_2.5 exposure and executive function. No significant associations were found between short-term PM_2.5 exposure or aperiodic exponents in tonic and phasic states, or periodic alpha oscillations in tonic state. Our results provided evidence that short-term PM_2.5 exposure was associated with executive dysfunction. Reduced alpha ERD was likely to be the underlying pathway through which PM_2.5 induced adverse effects on neuron activities during cognitive tasks.

This study aimed to assess the effectiveness of an online high-intensity interval training (HIIT) intervention and health education on the behaviors, mental health, and cognitive function of sedentary young females. A single-blinded, six-week, randomized controlled pilot trial involving 70 sedentary young Chinese females, aged 18–30 years, was conducted. An intervention group (IG) (n = 33) underwent a HIIT intervention and health education, while a waitlist group (WG) (n = 37) only received health education. In pre-, mid-, and post-tests, both groups filled out questionnaires about physical activity, sedentary behavior, and mental health. Cognitive functions were assessed at the pre- and post-tests by computer-administered cognitive tests. A mixed-effect model with repeated measures was used to analyze outcomes of interest. The retention rate of the IG and WG was 100% and 78.38%, respectively. The IG were found to have significantly increased rates of moderate-to-vigorous physical activity (MVPA) (M_diff = 940.61, p < 0.001, 95% confidence interval (95% CI): 576.67, 1304.55) from pre-test to post-test, while the WG demonstrated a more marked reduction in sedentary time (M_diff = −73.02, p = 0.038, 95% CI: −141.90, −4.14) compared with the IG in the post-test. Moreover, anxiety and stress levels were shown to significantly reduce in the IG over the six-week period (M_diff = −4.73, p = 0.002, 95% CI: −7.30, −2.15 and M_diff = −5.09, p = 0.001, 95% CI: −8.29, −1.89, respectively). In addition, we observed a significant improvement in verbal ability (p = 0.008, ${\mathsf{\eta }}_p^2$ = 0.19) following the HIIT intervention and effects of the interaction with time on processing speed (p = 0.050, ${\mathsf{\eta }}_p^2$ = 0.10) and episodic memory (p = 0.048, ${\mathsf{\eta }}_p^2$ = 0.11). Moreover, the IG had better global cognitive performance than the WG in the post-test (M_diff = 8.28, p = 0.003, 95% CI: 3.06, 13.50). In summary, both an online bodyweight HIIT intervention combined with health education, or health education alone, can effectively improve health-related behaviors, but the behavioral consequences may differ based on the emphasis of different intervention modalities. Furthermore, the “bodyweight HIIT plus health education” modality might be a more promising online intervention strategy to mitigate against negative emotions and improve cognitive function.

As physical activity benefits brain health whereas air pollution damages it, the cognitive response to these exposures may interact. This study aimed to assess the short-term joint effect of physical activity and air pollution on cognitive function in a panel of healthy young adults. We followed ninety healthy subjects aged around 22 years from September 2020 to June 2021 and measured their personal exposure to fine particulate matter (PM_2.5) (μg/m³) and daily accelerometer-based moderate-to-vigorous physical activity (MVPA) (min/day) in 4 one-week-long sessions over the study period. At the end of each measurement session, we assessed executive function using Stroop color-word test and collected resting-state electroencephalogram (EEG) signals. We found short-term PM_2.5 exposure damaged executive function (β_PM25 = 0.0064, p = 0.039) but physical activity could counterbalance it (β_MVPA = -0.0047, p = 0.048), whereby beta-3 wave played as a potential mediating role. MVPA-induced improvement on executive function was larger in polluted air (β_MVPA = -0.010, p = 0.035) than that in clean air (β_MVPA = -0.003, p = 0.45). To offset the negative effect of air pollution on cognitive function, individuals should do extra 13.6 min MVPA every day for every 10 μg/m³ increase in daily PM_2.5. This study implies that physical activity could be used as a preventive approach to compensate the cognitive damages of air pollution.

Exposure to fine particulate matter (PM_2.5) impairs cognition, while physical activity (PA) improves cognitive function. However, whether taking PA with PM_2.5 exposure is still beneficial to cognition remains unknown. We utilized national representative longitudinal data from the China Family Panel Study (CFPS), comprising a total sample of 108,099 from 2010 to 2018 in three waves. Cognitive performance and leisure-time PA were measured using the standard cognitive module and Godin-Shephard Leisure-Time Physical Activity Questionnaire. Gridded overall PM_2.5 and major chemical components of PM_2.5 were estimated using a two-stage machine learning model and matched to each participant based on their residential location. Mixed-effect models and difference-in-difference models were employed to investigate the individual and joint effects of total PM_2.5, PM_2.5 components, and leisure-time PA on cognition. Every 1 μg/m³ increase in PM_2.5 was associated with a -0.035 (95% confidence interval [CI] = -0.052, -0.018) point change in cognitive score. All PM_2.5 components exhibited negative associations with cognitive change, with black carbon (BC) contributing the most significant cognitive decline (β = -1.025, 95% CI = -1.367, -0.683). Every one-time (or one-hour) increase in leisure-time PA frequency (or PA time) per week was associated with an increase in cognitive score by 0.576 (0.270) points (PA frequency: 95% CI = 0.544, 0.608, PA time: 95% CI = 0.248, 0.293). PA frequency (β = -0.005, 95% CI = -0.006, -0.003) and PA time (β = -0.002, 95% CI = -0.003, -0.001) exhibited interactive effects with PM_2.5. Increased PA frequency and time were more beneficial to cognitive function in the low PM_2.5 exposure group compared to those exposed to high PM_2.5 levels. Moreover, relative to lower PM_2.5 exposure, the cognitive benefits of physically active individuals with higher PM_2.5 exposure were attenuated but still improved cognition when compared to those with no PA. Engaging in leisure-time PA provides cognitive benefits even under PM_2.5 exposure, although PM_2.5 exposure attenuates these benefits. Among all PM_2.5 components, BC demonstrated the most significant cognitive hazard and interaction with leisure-time PA. Promoting PA as a preventive measure may offer a cost-effective and convenient strategy to mitigate the negative impact of PM_2.5 exposure on cognition. There is no excuse to avoid PA under PM_2.5 exposure, as its cognitive benefits persist even in polluted environments.

Purpose: The current study was intended to assess the effect of a facilitated behavioral intervention based on the extended theory of planned behavior (TPB) on psychological constructs and physical activity among adolescents over a period of eight weeks. Methods: Students (n = 51, 12 ± 0.3 years of age) in the seventh grade at a junior middle school in China were randomly assigned to two groups: the intervention group (n = 24) and the control group (n = 27). Both groups were pre- and post-tested with the related psychological constructs of the extended TPB, along with behavioral measures of the Physical Activity Scale and ActiGraph accelerometer (model wGT3X-BT). The intervention group took part in 45 min classes once per week for 8 weeks, including five indoor theoretical courses and three outdoor basketball matches. The control group was not required to make any change to their normal school day. Also, 2 × 2 repeated measures analysis of variance (ANOVA) was conducted to compare the differences between the two groups, and then t-test was employed to compare the independent and paired differences. Results: Significant increases in pre–post subjective norms (SN) (p = 0.041, Cohen’s d = 0.62), perceived behavior control (PBC) (p = 0.023, Cohen’s d = 0.72), exercise intention (EI) (p = 0.043, Cohen’s d = 0.61), and self-efficacy (SE) (p = 0.035, Cohen’s d = 1.36) were observed in the intervention group. In addition, participants in the intervention group increased their exercise frequency (p < 0.001, Cohen’s d = 1.25) and intensity (p = 0.028, Cohen’s d = 0.68), especially their time spent on light intensity physical activity (light-PA%; p = 0.031, Cohen’s d = 0.68), and their percentage of sedentary time (SB%) was also reduced (from 68% ± 10% to 58% ± 7%, p < 0.001, Cohen’s d = 1.17). Furthermore, the intervention group showed significantly better performance in PBC (p = 0.032, Cohen’s d = 0.62), EI (p < 0.001, Cohen’s d = 1.32), SE (p < 0.001, Cohen’s d = 1.15), SB% (p < 0.001, Cohen’s d = 1.22), light-PA% (p < 0.001, Cohen’s d = 1.12), and total physical activity (TPA) (p = 0.015, Cohen’s d = 0.72) compared to the control group at the post-test. No significant pre post differences were observed for any psychological or behavioral variables in the control group, except for exercise frequency, but the values were still lower than those in the intervention group after the 8-week intervention (3.70 ± 0.72 versus 3.92 ± 0.83). Conclusion: The combined theory-based intervention was effective at improving psychological constructs and physical activity among seventh-grade adolescents in 8 weeks.