Objective To synthesise randomised controlled trials (RCTs) regarding the effects of chronic exercise interventions on different domain-specific executive functions (EFs) among children and adolescents. Design Systematic review with meta-analysis. Data sources PsycINFO, PubMed, SPORTDiscus, Academic Search Premier, Embase and Web of Science were searched. Eligibility criteria for selecting studies RCTs or cluster RCT design, which employ chronic exercise interventions and target healthy children (age 6–12 years) and adolescents (age 13–17 years). We defined chronic exercise as physical activity (PA) which consists of multiple exercise sessions per week and lasts for an extended period of time (typically over 6 weeks). Results We included 19 studies, with a total of 5038 participants. The results showed that chronic exercise interventions improved overall EFs (standardised mean difference (SMD)=0.20, 95% CI 0.09 to 0.30, p<0.05) and inhibitory control (SMD=0.26, 95% CI 0.08 to 0.45, P<0.05). In meta regression, higher body mass index was associated with greater improvements in overall EFs performance (β=0.03, 95% CI 0.0002 to 0.06, p<0.05), whereas age and exercise duration were not. In subgroup analysis by intervention modality, sports and PA programme (SMD=0.21, 95% CI 0.12 to 0.31, p<0.05) and curricular PA (SMD=0.39, 95% CI 0.08 to 0.69, p0.05). Interventions with a session length < 90 minutes improved overall EFs performance (SMD=0.24, 95%CI 0.10 to 0.39, p=0.02), but session length ≥ 90 minutes did not (SMD=0.05, 95%CI -0.03 to 0.14). No other moderator was found to have an effect. Conclusions Despite small effect sizes, chronic exercise interventions, implemented in curricular or sports and PA programme settings, might be a promising way to promote multiple aspects of executive functions, especially inhibitory control.

Background: Heart rate variability (HRV) as an accurate, noninvasive measure of the Autonomous Nervous System (ANS) can reflect mental health (e.g., stress, depression, or anxiety). Tai Chi and Yoga (Tai Chi/Yoga), as the most widely practiced mind–body exercises, have shown positive outcomes of mental health. To date, no systematic review regarding the long-lasting effects of Tai Chi/Yoga on HRV parameters and perceived stress has been conducted. Objective: To critically evaluate the existing literature on this topic. Methods: Five electronic databases (Web of Science, PubMed, Scopus, SportDiscus and Cochrane Library) were searched from the start of the research project to July 2018. Study selection, data extraction, and study quality assessment were independently carried out by two reviewers. The potentially identified randomized controlled trials (RCT) reported the useful quantitative data that were included only for meta-analysis. Results: meta-analysis of 17 medium-to-high quality RCTs showed significantly beneficial effects on HRV parameters (normalized low-frequency, Hedge’s g = −0.39, 95% CI −0.39 to −0.56, p < 0.001, I2 = 11.62%; normalized high-frequency, Hedge’s g = 0.37, 95% CI 0.22 to −0.52, p < 0.001, I2 = 0%; low-frequency to high-frequency ratio, Hedge’s g = −0.58, 95% CI −0.81 to −0.35, p < 0.001, I2 = 53.78%) and stress level (Hedge’s g = −0.80, 95% CI −1.17 to −0.44, p < 0.001, I2 = 68.54%). Conclusions: Stress reduction may be attributed to sympathetic-vagal balance modulated by mind–body exercises. Tai Chi/Yoga could be an alternative method for stress reduction for people who live under high stress or negative emotions.

Background: Exercise modes can be divided into open skill exercise (OSE) and closed skill exercise (CSE). While research has shown that these two exercise modes may have different effects on cognitive function, this possibility has not been systematically reviewed. Objective: The purpose of the present review was to objectively evaluate the research literature regarding the effects of OSE versus CSE on cognitive function. Methods: Six electronic databases (Web of Science, EMBASE, Google Scholar, PubMed, PsycINFO, and SPORTDiscus) were searched from inception dates to December 2018 for studies examining the associations of OSE and CSE with cognitive function. The literature searches were conducted using the combinations of two groups of relevant search items related to exercise modes (i.e., OSE and CSE) and cognitive function. Articles were limited to human studies in all age groups. Both intervention and observational studies with full text published in English-language peer-reviewed journals were considered eligible. The search process, study selection, data extraction, and study quality assessment were carried out independently by two researchers. Results: A total of 1,573 articles were identified. Fourteen observational and five intervention studies met the inclusion criteria. Twelve of the 14 observational studies found that OSE benefits cognitive function, and seven of these 14 observational studies supported superior effects of OSE compared with CSE for enhancing cognitive function. Three of the five intervention studies found that OSE (versus CSE) led to greater improvements in cognitive function in both children and older adults. Conclusion: Although the majority of studies in this review were observational cross-sectional designs, the review tends to support that OSE is more effective for improving some aspects of cognitive function compared with CSE. More rigorous randomized control trials with long-term follow-ups are needed in order to confirm these differential cognitive effects of the two exercise modes.

The primary aim of this study was to examine the associations of normal weight obesity (NWO) with physical fitness in Chinese university students. As a secondary aim, we assessed whether possible differences in physical fitness between students classified as NWO and normal weight non-obese (NWNO) were mediated by skeletal muscles mass. A total of 383 students (205 males and 178 females, aged 18–24 years) from two universities volunteered to participate in this study. Body height and weight were measured by standard procedures and body composition was assessed by bio-impedance analysis (InBody 720). NWO was defined by a BMI of 18.5–23.9 kg/m2 and a body fat percentage of > 20% or > 30% in male and female students, respectively. Physical fitness was measured using a 10-min intermittent endurance running test (Andersen test), countermovement jumps (CMJ) and a 5 × 5 m shuttle run test (5mSR). The level of leisure time physical activity (PA) was assessed by a questionnaire. 13.7% of male and 27.5% of female students were classified as NWO. Compared to NWNO, students classified as NWO showed a significantly poorer performance in the Andersen test (males: 1146 ± 70 m vs. 1046 ± 95 m, females: 968 ± 61 m vs. 907 ± 67 m, p < 0.001), CMJ (males: 55.0 ± 7.6 cm vs. 44.9 ± 7.5 cm, females: 39.8 ± 8.0 cm vs. 33.7 ± 5.9 cm, p < 0.001) and 5mSR (males: 18.7 ± 1.0 s vs. 20.0 ± 0.9 s, females: 21.1 ± 1.1 s vs. 22.4 ± 1.3 s, p < 0.001), respectively. The lower levels of physical fitness in NWO were partially explained by lower skeletal muscle mass (p < 0.001) both in male and female students. NWO was associated with poorer physical fitness and the relationship was partially mediated by lower skeletal muscle mass. The study indicated that attention should be paid for the potential hidden health risk in university students with normal body mass index but excessive fat mass.

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.