The effect of different high-intensity interval training protocols on cardiometabolic and inflammatory markers in sedentary young women: A randomized controlled trial.

Few studies have reported the cardiovascular health effects of different high-intensity interval training (HIIT) protocols among sedentary young women. We investigated the impact of a traditional HIIT programme and a high-intensity circuit training (HICT) programme on lipid profiles and inflammatory cytokine levels in sedentary young women. Forty-two women were randomly assigned to HICT (body weight-based training), HIIT (cycling-based training), or control groups (n = 14 each). HICT and HIIT participants completed an 8-week training programme of three sessions per week. Total cholesterol (TC), triglyceride, high- and low-density lipoprotein, leptin, resistin, tumour necrosis factor-alpha (TNF-α), interleukin-8, and interferon-gamma levels were measured before and after the intervention. Post-intervention, TC and leptin were decreased in the HICT group. The HICT group also demonstrated increased lean mass, upper and lower limb strength, and balance, while the HIIT group displayed improved lower limb strength. Additionally, the control group showed significant increases in triglyceride levels, weight, body mass index, and fat mass. In conclusion, although both HICT and HIIT interventions showed improvements in cardiovascular health and physical fitness, participants in the HICT group experienced more health benefits.

The effect of time-restricted eating combined with exercise on body composition and metabolic health: a systematic review and meta-analysis.

BACKGROUND: Time-restricted eating (TRE) has been increasingly popular, but its benefits in combination with exercise still need to be determined. OBJECTIVE: This systematic review and meta-analysis aimed to evaluate the efficacy of TRE combined with exercise compared with control diet with exercise in improving the body composition and metabolic health of adults. METHODS: Five electronic databases were searched for relevant studies. Randomized controlled trials (RCT) examining the effect of TRE combined with exercise on body composition and metabolic health in adults were included. All results in our meta-analysis were described as mean difference (MD) with 95% confidence interval (Cl). Study quality was assessed using the revised Cochrane Risk of Bias Tool and Grading of Recommendations Assessment, Development, and Evaluation assessment. RESULTS: In total, 19 RCTs comprising 568 participants were included in this systematic review and meta-analysis. TRE combined with exercise likely reduced the participants' body mass (MD = -1.86 kg, 95% CI [-2.75, -0.97]) and fat mass (MD = -1.52 kg, 95% CI [-2.07, -0.97]) when compared to the control diet with exercise. In terms of metabolic health, the TRE combined with the exercise group likely reduced triglycerides (MD = -13.38 mg/dl, 95% CI [-21.22, -5.54]) and may result in a reduction in low-density lipoprotein (MD = -8.52 mg/dl, 95% CI [-11.72, -5.33]) and a large reduction in leptin (MD -0.67 ng/ml; 95%CI [-1.02, -0.33]). However, TRE plus exercise exhibited no additional benefit on the glucose profile, including fasting glucose and insulin, and other lipid profiles, including total cholesterol and high-density lipoprotein levels, compared with the control group. CONCLUSIONS: Combining TRE with exercise may be more effective in reducing body weight and fat mass and improving lipid profile than control diet with exercise. Implementing this approach may benefit individuals aiming to achieve weight loss and enhance their metabolic well-being. REGISTRY AND REGISTRY NUMBER FOR SYSTEMATIC REVIEWS OR META-ANALYSES: CRD42022353834.

High-intensity interval training and cardiorespiratory fitness in adults: An umbrella review of systematic reviews and meta-analyses.

BACKGROUND: High-intensity interval training (HIIT) is characterized by repeated bouts of relatively intense exercise interspersed with recovery periods. Previous studies have evaluated this exercise strategy with various population subgroups, regimens, and comparator groups, limiting the generalizability of findings. We performed a novel umbrella review to generate an up-to-date synthesis of the available evidence regarding the effect of HIIT on cardiorespiratory fitness (CRF) in adults as compared to non-exercise control and traditional continuous forms of exercise such as moderate-intensity continuous training (MICT). METHODS: An umbrella review was conducted in accordance with the Preferred Reporting Items for Overviews of Reviews guideline. Seven databases (MEDLINE, EMBASE, Cochrane Database, CINAHL, Scopus, SPORTDiscus, and Web of Science) were searched until February 2024. Systematic reviews with meta-analyses comparing HIIT and active/non-active control conditions were included. Literature search, data extraction, and methodological quality assessment (AMSTAR-2) were conducted independently by two reviewers. RESULTS: Twenty-four systematic reviews with meta-analyses, representing 429 primary studies and 12 967 unique participants, met the inclusion criteria. Most of the systematic reviews received moderate-to-critically low AMSTAR-2 scores. The data showed that HIIT, including the particularly intense variant "sprint interval training" (SIT), significantly increases CRF in adults compared to non-exercise control (standardized mean difference [SMD]: 0.28 to 4.31; weighted mean difference [WMD]: 3.25 to 5.5 mL/kg/min) and MICT (SMD: 0.18 to 0.99; WMD: 0.52 to 3.76 mL/kg/min). This effect was consistently observed across specific groups of individuals (e.g., apparently healthy adults, individuals with overweight/obesity, older adults, and high-level athletes) and HIIT modalities (e.g., low-volume HIIT, whole-body HIIT, home-based HIIT, aquatic HIIT, and short SIT). CONCLUSION: Existing evidence from systematic reviews consistently supports the effect of HIIT on enhancing CRF in adults when compared to non-exercise control and MICT. Our findings offer a comprehensive basis that may potentially contribute to informing physical activity guidelines aimed at improving CRF in the general population.

Effects of intermittent dieting with break periods on body composition and metabolic adaptation: a systematic review and meta-analysis.

CONTEXT: Intermittent dieting incorporated with break periods (INT-B) has recently been promoted as an alternative dietary approach for optimal weight management. OBJECTIVE: This study assessed the effectiveness of INT-B compared with that of conventional continuous energy restriction (CER) for improving body composition and attenuating metabolic adaptation. DATA SOURCES: A systematic search was conducted on 6 databases using all available records until July 2023. DATA EXTRACTION: The extracted data included the lead author, year of publication, population characteristics, intervention protocols, duration, and adherence. DATA ANALYSIS: Random-effects meta-analyses were conducted for within-group and between-group comparisons of anthropometric and metabolic outcomes. Subgroup moderator analysis was performed for the types of INT-B, intervention duration, and population characteristics. RESULTS: Of the 1469 records, 12 randomized trials (with 881 participants) were included. Within-group analyses demonstrated significant improvements in body mass, fat mass, body mass index, body fat percentage, and waist circumference following both INT-B and CER, with no significant group differences. However, resting metabolic rate (RMR) was significantly reduced following CER only. The compensatory reduction in RMR was significantly smaller following INT-B compared with CER, suggesting a lesser degree of metabolic adaptation. INT-B had a more significant effect on RMR retention in individuals with overweight/obesity compared with resistance-trained individuals. CONCLUSION: This review provides up-to-date evidence for INT-B as a viable dietary strategy to improve body composition and attenuate metabolic adaptation. SYSTEMATIC REVIEW REGISTRATION: PROSPERO registration no. CRD42023448959.

Effect of Physical Exercise-Based Rehabilitation on Long COVID: A Systematic Review and Meta-analysis.

PURPOSE: The number of persons living with post-coronavirus disease 2019 (COVID-19) conditions or long COVID continues to rise worldwide; however, the etiology and the treatment of long COVID remain nebulous. Therefore, efficient, feasible, and cost-effective therapeutic strategies for a large population with long COVID remain warranted. Physical exercise-based rehabilitation is a promising strategy for long COVID, although its therapeutic effects remain to be determined. This systematic review and meta-analysis aimed to examine the effects of physical exercise-based rehabilitation on long COVID. METHODS: The electronic databases Medline, Embase, Global Health (Ovid), CINAHL (EBSCO), Web of Science, WHO Global Research Database on COVID-19, LitCovid, and Google Scholar were searched from their inception to November 2022. The identified articles were independently screened by three reviewers, and a random-effects model was used to determine the mean differences in the meta-analysis. RESULTS: Twenty-three studies involving 1579 individuals who had COVID-19 (752 women) were included. Physical exercise-based rehabilitation showed beneficial effects on long COVID-related symptoms characterized by dyspnea, fatigue, and depression, as well as on the 6-min walk test, forced expiratory volume in 1 s/forced vital capacity, and quality of life in people who had COVID-19. CONCLUSIONS: Physical exercise-based rehabilitation is a potential therapeutic strategy against long COVID and can be applied as a routine clinical practice in people who have recovered from COVID-19. However, customized physical exercise-based rehabilitation programs and their effects on specific types of long COVID require future large-scale studies.

Association of Sedentary Lifestyle with Risk of Acute and Post-Acute COVID-19 Sequelae: A Retrospective Cohort Study.

BACKGROUND: Evidence suggests that coronavirus disease 2019 (COVID-19) survivors could experience COVID-19 sequelae. Although various risk factors for COVID-19 sequelae have been identified, little is known about whether a sedentary lifestyle is an independent risk factor. METHODS: In this retrospective cohort study, 4850 participants self-reported their COVID-19 sequelae symptoms between June and August 2022. A sedentary lifestyle included physical inactivity (<150 min/week of moderate-to-vigorous intensity physical activity) and prolonged sedentary behavior (≥10 h/day) before the fifth COVID-19 wave was recorded. Logistic regression analysis was performed to determine the relationships between sedentary lifestyle and risk of acute and post-acute (lasting ≥2 months) COVID-19 sequelae. RESULTS: A total of 1443 COVID-19 survivors and 2962 non-COVID-19 controls were included. Of the COVID-19 survivors, >80% and >40% self-reported acute and post-acute COVID-19 sequelae, respectively. In the post-acute phase, COVID-19 survivors who were physically inactive had a 37% lower risk of insomnia, whereas those with prolonged sedentary behavior had 25%, 67%, and 117% higher risks of at least one symptom, dizziness, and "pins and needles" sensation, respectively. For the acute phase, prolonged sedentary behavior was associated with a higher risk of fatigue, "brain fog," dyspnea, muscle pain, joint pain, dizziness, and "pins and needles" sensation. Notably, sedentary behavior, rather than physical inactivity, was correlated with a higher risk of severe post-COVID-19 sequelae in both acute and post-acute phases. CONCLUSIONS: Prolonged sedentary behavior was independently associated with a higher risk of both acute and post-acute COVID-19 sequelae, whereas physical inactivity played contradictory roles in COVID-19 sequelae.

Effects of increasing light versus moderate-to-vigorous physical activity on cardiometabolic health in Chinese adults with obesity.

Increasing daily physical activity (PA) is a practical way to decrease the risk of cardiometabolic diseases, while the studies on exercise intensity remain limited. The purpose of the present study was to compare the effects of increasing light PA (LPA) or moderate-to-vigorous PA (MVPA) for 12 weeks on cardiometabolic markers in Chinese adults with obesity. Fifty-three adults were randomly assigned to the 1) control group, 2) LPA group, and 3) MVPA group in free-living settings. The intervention effects on body composition, cardiorespiratory fitness, and cardiometabolic biomarkers were analysed using a generalized estimated equation model adjusted for baseline values and potential confounders. Compared with the control group, the MVPA group showed improvements in body composition, lipids, C-peptide, monocyte chemoattractant protein-1 (MCP-1), interleukin-8, leptin, and E-selectin. A favourable change in triglycerides and E-selectin were observed in the LPA group when compared to the control group. Lastly, improvements in waist circumference, C-reactive protein, and MCP-1 were observed in the MVPA group when compared to those in the LPA group. Although increasing both LPA and MVPA improved certain cardiometabolic biomarkers, the latter may have more benefits. These findings imply that MVPA may reduce cardiometabolic disease risk more effectively than LPA, especially in Chinese adults with obesity.

Temporal trends in the physical fitness of Hong Kong children aged 6-12 years between 2003-04 and 2015-16.

Low physical fitness in childhood is linked with poor health now and in later life. This study estimated temporal trends in physical fitness for Hong Kong children aged 6-12 years from 2003-04 to 2015-16. Objectively measured body size and physical fitness data for 27,513 children were obtained from four population-representative surveys of Hong Kong primary school students. Temporal trends in means were estimated by population-weighted linear regression. Trends in distributional characteristics were visually described. Overall, there was a small increase in mean height (effect size (ES) = 0.20 (95%CI: 0.13, 0.28)), with a negligible increase (ES < 0.2) in mean body mass. When adjusted for trends in age, gender, and body size, there was a small decline in sit-and-reach performance (ES = -0.43 (95%CI: -0.43, -0.42)), a small improvement in 9-min run/walk performance (9-to-12-year-olds, ES = 0.26 (95%CI: 0.26, 0.27)), with negligible declines in handgrip strength, 6-min run/walk (6-to 8-year-olds), and sit-ups performance. Temporal trends were not always uniform across the population distribution, with declines in run/walk, sit-ups, and sit-and-reach performance generally largest in children with low fitness. Increased national health promotion strategies that address culturally specific factors are encouraged to further improve the existing trends, especially for children with low fitness.

Acute Physiological and Perceptual Responses to Whole-Body High-Intensity Interval Training Compared with Equipment-Based Interval and Continuous Training.

Low-volume, time-efficient high-intensity interval training (HIIT), which involves whole-body (WB) callisthenics exercises, has gained worldwide popularity in recent years. However, the physiological and perceptual impact of WB-HIIT in comparison to specialised, equipment-based training is relatively less studied. This study compared the acute physiological and perceptual responses to a single session of WB-HIIT, ergometer-based HIIT (ERG-HIIT) and conventional moderate-intensity continuous training (MICT). Fourteen physically inactive adults (age: 28.4 ± 6.5 years, VO2peak: 31.0 ± 6.2 mL· kg-1· min-1) underwent three main trials (WB-HIIT: 12 x 30-s high-intensity callisthenics workout; ERG: HIIT: 12 x 30-s high-intensity cycling bouts; MICT: 30-min cycling at 50% peak power output) in a randomized cross-over order 3-7 days apart. The mean session heart rate (HR) and perceived exertion were comparable across all three protocols (p > 0.05). WB-HIIT attained a similar peak HR (87.4 ± 9.4 %HRmax) as that of ERG-HIIT (83.0 ± 8.6 %HRmax), and significantly greater than that of MICT (78.7 ± 5.5 %HRmax, p = 0.001). However, WB-HIIT induced significantly higher blood lactate levels (7.2 ± 1.8 mmol/L) compared to both ERG-HIIT (5.1 ± 1.3 mmol/L, p < 0.05) and MICT (3.1 ± 1.5 mmol/L, p < 0.001). The participants reported higher self-efficacy and greater enjoyment with WB-HIIT compared to MICT (p < 0.05). The mean HR and perceived exertion responses to WB-HIIT are comparable to those of equipment-based HIIT and MICT; however, WB-HIIT results in greater metabolic strain than both other modalities. Despite this, the overall perceptual responses to WB-HIIT are positive, suggesting that it could be a viable exercise alternative, especially for individuals with limited exercise time and restricted access to facilities and equipment.

Methodological Quality of Systematic Reviews on Bodyweight Management Strategies for Children and Adolescents.

INTRODUCTION: Systematic reviews (SRs) synthesize empirical evidence from randomized controlled trials, to answer a research question. Methodological flaws in SRs can, however, reduce the trustworthiness of conclusions, subsequently hindering decision making. We aimed to appraise the methodological quality of existing SRs on bodyweight management strategies for children and adolescents. METHODS: We searched Cochrane Database of Systematic Reviews, MEDLINE, EMBASE, and SPORTDiscus. A MeaSurement Tool to Assess systematic Reviews (AMSTAR 2) was used to evaluate the methodological quality of SRs including 16 individual AMSTAR 2 domains and the total AMSTAR score. Association between bibliographical characteristics and total AMSTAR score of SRs was explored using multiple linear regression analysis. RESULTS: Three critical domain-specific items of AMSTAR 2 among the included SRs showed unsatisfactory results including (i) justifying deviation from their SR protocols, (ii) using comprehensive literature search strategies, and (iii) giving details of both included and excluded studies. "More recent publication year journal," "higher impact factor of the journal," and "greater number of review authors" were associated with better methodological quality of the included SRs. CONCLUSIONS: Future SRs' authors in the field of bodyweight management strategies for children and adolescents should improve the following criteria: (i) justify deviations from SR protocol, (ii) explain selection of the included study designs, (iii) use comprehensive literature search strategy, (iv) give details for both included and excluded studies, (v) report funding sources among included studies, and (vi) assess the potential impact of risk of bias among the included studies on meta-analysis results.

Temporal Trends in the Physical Fitness of Hong Kong Adolescents Between 1998 and 2015.

Low physical fitness in adolescence is linked with increased cardiometabolic risk and early all-cause mortality. This study aimed to estimate temporal trends in the physical fitness of Hong Kong adolescents aged 12-17 years between 1998 and 2015. Physical fitness (9-min run/walk, sit-ups, push-ups, and sit-and-reach) and body size data in a total of 28,059 adolescents tested across five population-representative surveys of Hong Kong secondary school pupils, were reported. Temporal trends in means were estimated at the gender-age level by best-fitting sample-weighted linear regression, with national trends estimated by a post-stratified population-weighting procedure. Overall, there were small declines in 9-min run/walk (effect size (ES)=-0.29 (95%CI: -0.32, -0.26)) and sit-ups performance (ES=-0.24 (95%CI: -0.27, -0.21)), with negligible changes in push-ups and sit-and-reach performance. There were small concurrent increases in both mean height and body mass, with a negligible increase in sum of skinfolds. Trends in mean physical fitness and body size/were not always uniform across the population distribution. The small declines in mean 9-min run/walk and sit-ups performance for Hong Kong adolescents are suggestive of corresponding declines in cardiorespiratory fitness and abdominal/core endurance, respectively. Increased national health promotion strategies are required to improve existing trends.

A novel physical functioning test to complement subjective questionnaires in chronic low back pain assessments.

BACKGROUND CONTEXT: Lifting disability commonly affects patients with chronic low back pain (CLBP) and may not correlate with the existing lifting-related physical assessment tests, such as the loaded forward reach (LFR) test. PURPOSE: The Lift and Place (LAP) test was developed to assess lifting disability in CLBP based on known risk factors. The LAP test was compared with established physical assessment test, including the LFR test and self-reported disability questionnaires. STUDY DESIGN/SETTING: This cross-sectional study measured self-reported disability questionnaires along with LAP and other physical assessment test results PATIENT SAMPLE: Eighty three CLBP and 82 asymptomatic participants aged 18 to 55 with normal BMI according to WHO classification. OUTCOME MEASURES: Oswestry disability index (ODI), Roland-Morris disability questionnaire (RMDQ), Numerical Pain Rating Scale, Trunk Extensor Endurance test, 5 Repetition Sit-To-Stand test, LAP and LFR test. METHODS: Physical assessment test scores were compared between the two groups. The correlation of assessment test scores with ODI and RMDQ in patients with CLBP was calculated. Receiver operating characteristic (ROC) curve analysis was performed to calculate the area under the curve (AUC) of each assessment tests. Assessment tests, ODI, and RMDQ were measured twice for CLBP patients on separate days to calculate the test-retest intraclass correlation (ICC) reliability. Two researchers scored the assessment tests independently to calculate the inter-rater ICC. RESULTS: Patients with CLBP were slower in the LAP test (CLBP vs asymptomatic: 21.6±4.9 s vs 18.6±3.6 s) and had shorter reach in the LFR test (CLBP vs asymptomatic: 33.6±6.0 cm vs 36.3±6.6 cm). The LAP was correlated with both ODI (r=0.418) and RMDQ (r=0.390), while the LFR was not. In the ROC analysis, the LAP and LFR bore AUCs of 0.685 and 0.379, respectively. Their test-retest ICCs were 0.913 and 0.858, and their inter-rater ICCs were 0.997 and 0.969, respectively. CONCLUSIONS: The LAP test demonstrated higher reliability and significant correlation with the ODI and RMDQ, indicating its potential as performance assessment for lifting disability in CLBP. Further studies should investigate the use of LAP and other physical assessments for rapid CLBP screening.

Associations Between Perceived Social Support, Perceived Competence, and Physical Activity in Hong Kong Children With Disabilities During the COVID-19 Pandemic.

This study aimed to examine the associations between perceived social support, perceived competence, and physical activity in children with physical and intellectual disabilities during the COVID-19 pandemic. During the third wave of the pandemic in Hong Kong (i.e., July through December 2020), 291 participants age 6-17 years from 27 special schools were included. After controlling for demographic variables, the total variance explained by perceived social support and perceived competence was 24%, F(2, 240) = 12.42, p < .001, with perceived competence having a stronger association with physical activity (ß = 0.29, p < .001) than perceived social support (ß = 0.07, p = .22). This study highlights two key facilitators for shaping physical activity involvement among children with disabilities during the COVID-19 pandemic.

Effects of Wearing a Mask During Exercise on Physiological and Psychological Outcomes in Healthy Individuals: A Systematic Review and Meta-Analysis.

BACKGROUND: Wearing face masks in public is an effective strategy for preventing the spread of viruses; however, it may negatively affect exercise responses. Therefore, this review aimed to explore the effects of wearing different types of face masks during exercise on various physiological and psychological outcomes in healthy individuals. METHODS: A literature search was conducted using relevant electronic databases, including Medline, PubMed, Embase, SPORTDiscus, Web of Science, and Cochrane Central Register of Controlled Trials on April 05, 2022. Studies examining the effect of mask wearing (surgical mask, cloth mask, and FFP2/N95 respirator) during exercise on various physiological and psychological parameters in apparently healthy individuals were included. For meta-analysis, a random effects model was used. Mean difference (MD) or standardized MD (SMD) with 95% confidence intervals (CI) were calculated to analyze the total effect and the effect in subgroups classified based on face mask and exercise types. The quality of included studies was examined using the revised Cochrane risk-of-bias tool. RESULTS: Forty-five studies with 1264 participants (708 men) were included in the systematic review. Face masks had significant effects on gas exchange when worn during exercise; this included differences in oxygen uptake (SMD - 0.66, 95% CI - 0.87 to - 0.45), end-tidal partial pressure of oxygen (MD - 3.79 mmHg, 95% CI - 5.46 to - 2.12), carbon dioxide production (SMD - 0.77, 95% CI - 1.15 to - 0.39), and end-tidal partial pressure of carbon dioxide (MD 2.93 mmHg, 95% CI 2.01-3.86). While oxygen saturation (MD - 0.48%, 95% CI - 0.71 to - 0.26) decreased slightly, heart rate was not affected. Mask wearing led to higher degrees of rating of perceived exertion, dyspnea, fatigue, and thermal sensation. Moreover, a small effect on exercise performance was observed in individuals wearing FFP2/N95 respirators (SMD - 0.42, 95% CI - 0.76 to - 0.08) and total effect (SMD - 0.23, 95% CI - 0.41 to - 0.04). CONCLUSION: Wearing face masks during exercise modestly affected both physiological and psychological parameters, including gas exchange, pulmonary function, and subjective discomfort in healthy individuals, although the overall effect on exercise performance appeared to be small. This review provides updated information on optimizing exercise recommendations for the public during the COVID-19 pandemic. SYSTEMATIC REVIEW REGISTRATION NUMBER: This study was registered in the International Prospective Register of Systematic Review (PROSPERO) database (registration number: CRD42021287278).

The Associations Between Accelerometer-Measured Physical Activity Levels and Mental Health in Children and Adolescents with Intellectual Disabilities During the COVID-19 Pandemic.

To examine the associations between physical activity (PA) levels and mental health in children and adolescents with intellectual disabilities (IDs) during the COVID-19 pandemic, 117 participants aged between 6 and 17 years with IDs from 10 Hong Kong special schools were included. There were positive dose-response associations between PA (i.e., light PA, moderate PA, and vigorous PA) and mental health, and participants with higher levels of moderate-to-vigorous PA (MVPA) and self-concept (SC) had better social quality of life (QoL) than those with lower levels of MVPA and SC. Moreover, personal and environmental factors such as age, body mass index, school, sex, ID level, and parental education level influenced the PA levels and QoL in children and adolescents with IDs.

Moderate-vigorous physical activity attenuates premature senescence of immune cells in sedentary adults with obesity: a pilot randomized controlled trial.

Despite the well-known senolytic effects of physical exercise on immune cells in older adults, the effect of physical activity (PA) on premature immune senescence in sedentary adults with obesity remains largely unknown. This pilot study aimed to investigate the role of objectively measured physical behaviors and Fitbit watch-based free-living PA intervention in premature senescence of immune cells in sedentary adults with obesity. Forty-five participants were recruited in the cross-sectional analysis, and forty of them further participated in the randomized controlled trial. We found that objectively measured moderate-vigorous PA was independently and inversely correlated with the expression of p16INK4a and p21Cip1 in the peripheral blood mononuclear cell (PBMCs) of adults with obesity; however, chronological age, body mass index, body fat, maximal oxygen consumption, light PA, sedentary behaviors, and sleep duration were not. More importantly, the 12-week PA intervention mitigated the elevated p16INK4a levels in PBMCs, though it showed no effect on p21Cip1 and senescence-associated secretory phenotypes. Taken together, physical inactivity is an independent determinant of premature senescence in immune cells, while the 12-week PA intervention is a promising strategy to alleviate premature immune senescence in adults with obesity.

Effects of a blended classroom-based intervention on aerobic fitness, motor skills, inhibition, and daytime sleepiness among Hong Kong children.

In response to the all-round development of primary school children, this study aimed to evaluate the effectiveness of a blended intervention program on children's health-related outcomes of aerobic fitness, motor skills, inhibition and daytime sleepiness in classroom settings. Three experimental conditions include: (1) the "Stand + Move" group combining sit-stand desks and physical activity (PA) recess, (2) "Move" group with PA recess only, and (3) Control group (CG; normal class schedule). A total of 64 primary school children (37.5% girls and 62.5% boys, M [SD] = 9.6 [0.61], BMI mean = 17.0 ± 3.0) participated in all assessments, including aerobic fitness, motor skills, inhibitory control, and daytime sleepiness. The baseline data collection starts from January 2019, with the intervention lasting for 13 weeks and followed by post-intervention and follow up tests conducted in July and October 2019. There was a significant interaction effect on aerobic fitness [F (2,76) = 10.62, p < 0.001, η2 = 0.22] after the intervention period, whereas no significant interaction was observed for other variables. Significant main effects were observed in aerobic fitness (pre - post: -11.75 and -7.22) for both experimental groups, with the blended group showing greater improvements immediately post the test, while motor skills only showed a significant increase at the three-month follow-up, with the greatest increase in the blended group (pre-follow-up: -2.50). For inhibition control and daytime sleepiness, better improvements were shown for the experimental groups than for the control group. The blended designed intervention, by incorporating multiple components as an innovative strategy to reconstruct children's traditional classroom environment in Hong Kong, has demonstrated improved physical and psychological development of school children. Clinical trial registration: ChiCTR, ChiCTR2000035038. Registered 29 July 2020 - Retrospectively registered. http://www.chictr.org.cn/hvshowproject.aspx?id=46038.

Active Healthy Kids Global Alliance Global Matrix 4.0-A Resource for Physical Activity Researchers.

BACKGROUND: This brief report provides an overview of the Active Healthy Kids Global Alliance (AHKGA); an introduction to the Global Matrix 4.0; an explanation of the value and opportunities that the AHKGA efforts and assets provide to the physical activity research, policy, practice, and advocacy community; an outline of the series of papers related to the Global Matrix 4.0 in this issue of the Journal of Physical Activity and Health; and an invitation for future involvement. METHODS: The AHKGA was formed to help power the global movement to get kids moving. In 2019-2021, we recruited countries to participate in the Global Matrix 4.0, a worldwide initiative to assess, compare, and contrast the physical activity of children and adolescents. RESULTS: A total of 57 countries/jurisdictions (hereafter referred to as countries for simplicity) were recruited. The current activities of the AHKGA are summarized. The overall findings of the Global Matrix 4.0 are presented in a series of papers in this issue of the Journal of Physical Activity and Health. CONCLUSIONS: The Global Matrix 4.0 and other assets of the AHKGA are publicly available, and physical activity researchers, practitioners, policy makers, and advocates are encouraged to exploit these resources to further their efforts.

The Associations Among Physical Activity, Quality of Life, and Self-Concept in Children and Adolescents With Disabilities: A Moderated Mediation Model.

Objectives: This study aimed to examine a moderated mediation model of the associations among physical activity (PA), quality of life (QoL), and self-concept (SC) in children and adolescents with physical disabilities (PDs) and intellectual disabilities (IDs). Materials and Methods: A total of 288 children and adolescents with PDs and IDs, aged between 6 and 17 years, were recruited from 16 special schools in Hong Kong. PA, QoL, and SC were measured using the Physical Activity Questionnaire for Older Children (PAQ-C), Paediatric Quality of Life Inventory (PedsQL), and Physical Self-Description Questionnaire Short Form, respectively. Mediation (i.e., PA, QoL, and SC) and moderation analyses (i.e., age, sex, and parental education level) were conducted by structural equation modelling (SEM) using the M plus and PROCESS macro for SPSS. Results: Physical activity (PA) was positively associated with SC (PDs: ß = 0.373; IDs: ß = 0.343), and SC significantly mediated the associations between PA and QoL in children and adolescents with PDs (parent proxy-report QoL: ß = 0.114; self-report QoL: ß = 0.141) and IDs (self-report QoL: ß = 0.204). The mediating effects of SC accounted for 16 and 15% of the total effects of PA on QoL (parent proxy-report and self-report) respectively, in participants with PDs, and 8 and 4%, respectively, in those with IDs. Males and participants with higher parental education levels reported stronger associations among PA, QoL, and SC than their counterparts. Conclusion: This study supports mediating and moderating effects on the associations among PA, QoL, and SC in children and adolescents with PDs and IDs. Future researchers should consider PA intervention in mental health services and provide tailor-made PA programmes based on personal and environmental factors for children and adolescents with disabilities.

Effect of game-based high-intensity interval training program on the executive function of children with ADHD: Protocol of a randomized controlled trial.

BACKGROUND: Attention-deficit/hyperactivity disorder (ADHD) is a common developmental disorder in childhood, with a 5%-6% worldwide prevalence. Children with ADHD often demonstrate impaired executive function, which is closely related to the development of the commonly observed behavioral problems such as inattention, impaired inhibition, and hyperactivity. The purpose of this study is to examine whether a game-based high-intensity interval training (HIIT) program can improve the executive function of children with ADHD, compared with a traditional structured aerobic exercise program and a non-treatment control group. METHODS/DESIGN: A total of 42 children with ADHD will be recruited to participate in this three-arm school-based randomized controlled trial. An 8-week specially designed game-based HIIT (GameHIIT) program and a traditional game-based structured aerobic exercise (GameSAE) program will be delivered to those children randomly assigned to these two intervention groups, while the children in the control group will maintain their regular physical activity over the same period. A number of outcome measures including executive function, cerebral hemodynamic response, physical activity, physical fitness, and enjoyment and adherence to the intervention will be assessed for both groups at baseline (T0), immediately after the intervention period (T1), and after the follow-up period (T2). DISCUSSION: HIIT has recently emerged as a feasible and efficacious strategy for increasing physical health outcomes and cognitive function, including executive function, in healthy young people. However, research has yet to investigate whether the executive function of children with ADHD can be effectively enhanced through HIIT. If, as hypothesized, GameHIIT program improves outcomes for children with ADHD, the present research will inform the development of targeted exercise programs that can be more broadly used with this particular population.