The purpose of this study was to evaluate the effects of high-intensity interval training (HIIT) and moderate-intensity continuous training (MICT) on cardiovascular disease (CVD) risk factors in adults with overweight and obesity. Twenty-two articles were included by searching six databases, the total number of subjects was 620 in these articles. Outcomes were synthesised using a random-effects meta-analysis of the Standardized mean difference (SMD) in CVD risk factors. HIIT and MICT resulted in statistically significant reductions in Weight, BMI, fat%, total cholesterol(TC), and improvement in VO_2max. Compared with MICT, subgroup of durations of HIIT training interval ≥2 min can significantly increase VO_2max (SMD = 0.444, 95% CI:0.037~0.851,P = 0.032), subgroup of energy expenditure of HIIT equal to MICT can significantly increase VO_2max (SMD = 0.399, 95% CI:0.106~0.692,P = 0.008). HIIT appears to provide similar benefits to MICT for improving body composition, VO_2maxand TC, but HIIT spent less time than MICT by 9.7 min on one session. HIIT is superior to MICT in improving cardiopulmonary fitness when durations of HIIT training interval ≥2 min or energy expenditure of HIIT same as MICT. PROSPERO ID: CRD42016045835.

Background: About 70% of children and adolescents worldwide do not meet the recommended level of physical activity (PA), which is closely associated with physical, psychological, and cognitive well-being. Nowadays, the use of technologies to change PA is of interest due to the need for novel, more effective intervention approaches. The previous meta-analyses have examined smartphone-based interventions and their impact on PA in adults, but evidence in children and adolescents still needs further research. Objective: This systematic review and meta-analysis aimed to determine the effectiveness of smartphone-based interventions for improving PA in children and adolescents. Methods: Five electronic databases (PubMed, Web of Science, OVID, Scopus, and the China National Knowledge Infrastructure) were searched up to June 29, 2020. Randomized controlled trials with a control group that examine the effect of smartphone interventions on PA among children and adolescents were included. Bias risks were assessed using the Cochrane collaboration tool. Meta-analysis was performed to assess the pooled effect on PA using a random effects model. Subgroup analyses were conducted to examine the potential modifying effects of different factors (eg, types of intervention, intervention duration, age, measurement, study quality). Results: A total of 9 studies were included in this review, including 4 mobile app interventions, 3 SMS text messaging interventions, and 2 app + SMS text messaging interventions. In general, the risk of bias of included studies was low. Compared with the control group, the use of smartphone intervention significantly improved PA (standardized mean difference [SMD] 0.44, 95% CI 0.11-0.77, P=.009), especially for total PA (TPA; weighted mean difference [WMD] 32.35, 95% CI 10.36-54.33, P=.004) and daily steps (WMD 1185, 95% CI 303-2068, P=.008), but not for moderate-to-vigorous PA (WMD 3.91, 95% CI –1.99 to 9.81, P=.19). High statistical heterogeneity was detected (I2=73.9%, P<.001) for PA. Meta-regression showed that duration (β=–.08, 95% CI –0.15 to –0.01, n=16) was a potential factor for high heterogeneity. The results of subgroup analyses indicated that app intervention (SMD 0.76, 95% CI 0.23-1.30, P=.005), children (SMD 0.64, 95% CI 0.10-1.18, P=.02), “≤8 weeks” (SMD 0.76, 95% CI 0.23-1.30, P=.005), objective measurement (SMD 0.50, 95% CI 0.09-0.91, P=.02), and low risk of bias (SMD 0.96, 95% CI 0.38-1.54, P=.001) can significantly improve PA. Conclusions: The evidence of meta-analysis shows that smartphone-based intervention may be a promising strategy to increase TPA and steps in children and adolescents. Currently, app intervention may be a more effective strategy among smartphone intervention technologies. To extend the promise of smartphone intervention, the future needs to design comparative trials among different smartphone technologies. Trial Registration: PROSPERO CRD42019148261; https://tinyurl.com/y5modsrd

“Living High-Training Low” (LHTL) is effective for the improvement of athletic ability; however, little is known about the effect of LHTL on obese individuals. The present study determined whether LHTL would have favorable influence on body composition, rebalance the appetite hormones, and explore the underlying mechanism. Adolescents with obesity [body mass index (BMI) >30 kg/m2] were randomly assigned to “Living Low-Training Low” (LLTL, n = 19) group that slept in a normobaric normoxia condition and the LHTL (n = 16) group slept in a normobaric hypoxia room (14.7% PO2 ∼2700 m). Both groups underwent the same aerobic exercise training program. Morphological, blood lipids, and appetite hormones were measured and assessed. After the intervention, the body composition improved in both groups, whereas reductions in body weight (BW), BMI, and lean body mass increased significantly in the LHTL group (all, P < .05). In the LLTL group, cholecystokinin (CCK) decreased remarkably (P < .05) and CCK changes were positively associated with changes in BW (r = 0.585, P = .011) and BMI (r = 0.587, P = .010). However, in the LHTL group, changes in plasma glucagon-like peptide-1 (GLP-1) and interleukin-6 (IL-6) levels, positively correlated with each other (r = 0.708, P = .015) but negatively with BW changes (r = −0.608, P = .027 and r = −0.518, P = .048, respectively). The results indicated that LHTL could induce more weight loss safely and efficiently as compared to LLTL and increase the plasma GLP-1 levels that may be mediated by IL-6 to rebalance the appetite. Thus, an efficient method to treat obesity and prevent weight regain by appetite rebalance in hypoxia condition was established.

Background: Physical literacy (PL) can positively affect the health of children, adolescents, and adults, and is closely related to cardiorespiratory fitness (CRF). Objective: To perform a systematic review and meta-analysis to examine the relationship between overall physical literacy (PL) and CRF in children and adolescents. Methods: Cross-sectional, cohort and experimental studies on the relationship between PL and CRF in children and adolescents were collected by searching the Web of Science Core Collection, PubMed, EBSCOhost, ScienceDirect, Cochrane Library and China National Knowledge Infrastructure (CNKI) databases. Based on the characteristics of the included literature, PL was divided into physical competence (PC), daily behavior (DB), knowledge and understanding (K&U), and motivation and confidence (M&C). R 4.3.6 was used to analyze the combined effect size of PL and the relationships of the four dimensions with CRF among children and adolescents. Results: A total of 21 articles were included, 42.9% of which were published after 2020, involving a total of 43,352 children and adolescents from 23 countries or regions. The characteristics of the included studies showed that, except for the K&U of children and adolescents aged 13–18 years, the K&U of other age groups and the PL, PC, DB, M&C of all age groups were significantly positively correlated with CRF. Furthermore, the results of male and female samples in all included studies were the same. The results of the meta-analysis indicated that PL (COR = 0.64, 95% CI 0.58, 0.70), PC (COR = 0.74, 95% CI 0.69, 0.79), DB (COR = 0.49, 95% CI 0.40, 0.57), K&U (COR = 0.41, 95% CI 0.23, 0.56), and M&C (COR = 0.45, 95% CI 0.41, 0.49) were significantly positively correlated with CRF. Regarding DB, total physical activity (TPA) was positively correlated with CRF (COR = 0.49, 95% CI = 0.40, 0.57). Moderate to vigorous physical activity (MVPA), vigorous physical activity (VPA) and high physical activity (HPA) were positively correlated with CRF (COR = 0.16, 95% CI 0.09, 0.22; COR = 0.33, 95% CI 0.22, 0.43; COR = 0.38, 95% CI 0.13, 0.58), but light physical activity (LPA) was negatively correlated with CRF (COR = − 0.20, 95% CI − 0.32, 0.06). Conclusion: PL and CRF are positively correlated among children and adolescents, suggesting that the development of physical literacy has a wide range of effects on children and adolescents’ cardiopulmonary health and that these effects are not limited by PL and its various dimensions or sex. In addition, to exert the positive effect of daily activities on cardiopulmonary health, the intensity of physical activity should reach a moderate level or above.

Early childhood is a critical period for development of cognitive function, but research on the association between physical activity and cognitive function in preschool children is limited and inconclusive. This study aimed to examine the association between technology-assessed physical activity and cognitive function in preschool children. A cross-sectional analysis of baseline data from the Physical Activity and Cognitive Development Study was conducted in Shanghai, China. Physical activity was measured with accelerometers for 7 consecutive days, and cognitive functions were assessed using the Chinese version of Wechsler Young Children Scale of Intelligence (C-WYCSI). Linear regression analyses were used to assess the association between physical activity and cognitive function. A total of 260 preschool children (boys, 144; girls, 116; mean age: 57.2 ± 5.4 months) were included in analyses for this study. After adjusting for confounding factors, we found that Verbal Intelligence Quotient, Performance Intelligence Quotient, and Full Intelligence Quotient were significantly correlated with light physical activity, not moderate to vigorous physical activity, in boys. Standardized coefficients were 0.211, 0.218, and 0.242 (all p < 0.05) in three different models, respectively. However, the correlation between physical activity and cognitive functions were not significant in girls (p > 0.05). These findings suggest that cognitive function is apparently associated with light physical activity in boys. Further studies are required to clarify the sex-specific effect on physical activity and cognitive functions.

Objective: Engaging in physical activity (PA) plays an important role in promoting physical and mental health, but the PA data for Chinese preschool children are lacking. This study aims to objectively assess the PA levels of preschool children in Shanghai, China and to evaluate their PA levels relative to age-specific recommendations. Design, setting and participants: A cross-sectional study was conducted among preschool children in Shanghai, city of China. There were a total of 303 preschool children (boys, 174; girls, 129) recruited from eight kindergarten classes in the Yangpu and Baoshan Districts of Shanghai. Main outcome measures: Daily PA was assessed using ActiGraph GT3X⁺ accelerometers for seven consecutive days. Children were required to have data from at least 2 weekdays and 1 weekend day, with a minimum daily wear time of 480 min to be included in the analysis. Results: Preschool children in Shanghai accumulated, on average, 70.9 min of moderate-to-vigorous PA (MVPA) and 168.0 min of total PA (TPA) per day (d). Boys engaged in more MVPA and TPA than girls (72.8 min/day vs 68.3 min/day and 171.9 min/day vs 162.9 min/day, respectively). Overall, 72.9% of the participants met the age-specific recommendations of MVPA, while 35.3% met TPA recommendations. Conclusions: Findings of this study warn of the insufficiency of PA in Shanghai preschool children, suggesting there is substantial room to improve their PA. Trial registration number: ChiCTR-OOC-15007439; Results.