Association of daily sitting time and leisure-time physical activity with body fat among U.S.adults

Background:Prolonged sitting and reduced physical activity lead to low energy expenditures.However,little is known about the joint impact of daily sitting time and physical activity on body fat distribution.We investigated the independent and joint associations of daily sitting time and physical activity with body fat among adults.Methods:This was a cross-sectional analysis of U.S.nationally representative data from the National Health and Nutrition Examination Survey2011-2018 among adults aged 20 years or older.Daily sitting time and leisure-time physical activity(LTPA)were self-reported using the Global Physical Activity Questionnaire.Body fat(total and trunk fat percentage)was determined via dual X-ray absorptiometry.Results:Among 10,808 adults,about 54.6%spent 6 h/day or more sitting;more than one-half reported no LTPA(inactive)or less than 150 min/week LTPA(insufficiently active)with only 43.3%reported 150 min/week or more LTPA(active)in the past week.After fully adjusting for sociodemographic data,lifestyle behaviors,and chronic conditions,prolonged sitting time and low levels of LTPA were associated with higher total and trunk fat percentages in both sexes.When stratifying by LTPA,the association between daily sitting time and body fat appeared to be stronger in those who were inactive/insuufficiently active.In the joint analyses,inactive/insuufficiently active adults who reported sitting more than 8 h/day had the highest total(female:3.99%(95%confidence interval(95%CI):3.09%-4.88%);male:3.79%(95%CI:2.75%-4.82%))and trunk body fat percentages(female:4.21%(95%CI:3.09%-5.32%);male:4.07%(95%CI:2.95%-5.19%))when compared with those who were active and sitting less than 4 h/day.Conclusion:Prolonged daily sitting time was associated with increased body fat among U.S.adults.The higher body fat associated with 6 h/day sitting may not be offset by achieving recommended levels of physical activity.

Leisure-time physical activity and all-cause mortality and cardiovascular disease in adults with type 2 diabetes:Cross-country comparison of cohort studies

Purpose:This study aimed to quantify the dose-response association and the minimal effective dose of leisure-time physical activity(PA)to prevent mortality and cardiovascular disease in adults with type 2 diabetes.Methods:Cross-country comparison of 2 prospective cohort studies including 14,913 and 17,457 population-based adults with type 2 diabetes from the UK and China.Baseline leisure-time PA was self-reported and categorized by metabolic equivalent hours per week(MET-h/week)according to World Health Organization recommendations:none,below recommendation(>0-7.49 MET-h/week);at recommended level(7.5-14.9 MET-h/week);above recommendation(>15 MET-h/week).Mortality and cardiovascular disease data were obtained from national registries.Results:During a median follow-up of 12.4 and 9.7 years,in the UK and China cohorts,repectively,higher levels of leisure-time PA were inversely associated with all-cause(1571 and 2351 events)and cardiovascular mortality(392 and 1060 events),mostly consistent with a linear dose-response relationship.PA below,at,and above recommendations,compared with no activity,yielded all-cause mortality hazard ratios of0.94(95%confidence interval(95%CI):0.79-1.12),0.90(95%CI:0.74-1.10),and 0.85(95%CI:0.70-1.02)in British adults and 0.87(95%CI:0.68-1.10),0.88(95%CI:0.74-1.03),and 0.77(95%CI:0.70-0.85)in Chinese adults.Associations with cardiovascular mortality were more pronounced in British adults(0.80(95%CI:0.58-1.11),0.75(95%CI:0.52-1.09),and 0.69(95%CI:0.48-0.97))but less pronounced in Chinese adults(1.06(95%CI:0.76-1.47),1.01(95%CI:0.80-1.28),and 0.79(95%CI:0.69-0.92)).PA at recommended levels was not associated with lower rates of major adverse cardiovascular events(2345 and 4458 events).Conclusion:Leisure-time PA at the recommended levels was not convincingly associated with lower mortality and had no association with risk of major adverse cardiovascular events in British or Chinese adults with type 2 diabetes.Leisure-time PA above current recommendations may be needed to prevent cardiovascular disease and premature mortality in adults with type 2 diabetes.

A marathon,not a sprint:Increasing population physical activity as a legacy of sports mega-events

1.Legacy matters The withdrawal of Australia as hosts for the Commonwealth Games in 2026 demonstrates that large international sporting events are more than just sporting mastery,medals,and memories.Money also matters.1 The cost of hosting a major international tournament is eye-wateringly high.Host governments need to show that the billions of dollars of investment deliver a return beyond sporting glory to justify the resources that are spent.

A randomized controlled trial of Promoting Physical Activity in Regional and Remote Cancer Survivors(PPARCS)

Background:Physical activity(PA)is important for cancer survivors.Trials of remotely delivered interventions are needed to assist in reaching under-served non-metropolitan cancer survivors.The objective of this study was to ascertain whether wearable technology,coupled with health coaching was effective in increasing PA in breast and colorectal cancer survivors living in regional and remote areas in Australia.Methods:Cancer survivors from 5 states were randomized to intervention and control arms.Intervention participants were given a Fitbit Charge 2TMand received up to 6 telephone health coaching sessions.Control participants received PA print materials.Accelerometer assessments at baseline and 12 weeks measured moderate-to-vigorous PA(MVPA),light PA,and sedentary behavior.Results:Eighty-seven participants were recruited(age=63±11 years;74(85%)female).There was a significant net improvement in MVPA of 49.8 min/week,favoring the intervention group(95%confidence interval(95%CI):13.6-86.1,p=0.007).There was also a net increase in MVPA bouts of 39.5 min/week(95%CI:11.9-67.1,p=0.005),favoring the intervention group.Both groups improved light PA and sedentary behavior,but there were no between-group differences.Conclusion:This’s the first study to demonstrate that,when compared to standard practice(i.e.,PA education),a wearable technology intervention coupled with distance-based health coaching,improves MVPA in non-metropolitan cancer survivors.The results display promise for the use of scalable interventions using smart wearable technology in conjunction with phone-based health coaching to foster increased PA in geographically disadvantaged cancer survivors.

Global prevalence and gender inequalities in at least 60 min of self-reported moderate-to-vigorous physical activity 1 or more days per week:An analysis with 707,616 adolescents

Background:Guidelines recommend that adolescents should accumulate an average of 60 min per day of moderate-to-vigorous physical activity(MVPA).However,using only this cut-off could hide important information.For instance,from a population-level point of view,increasing physical activity for those with no or low physical activity could provide more health benefits than increasing physical activity for those with intermediate levels.Also,including a more sensitive cut-point of≥1 days per week could be an additional strategy for identifying those with low access/opportunities for physical activity practice.Thus,the current study aims to estimate the prevalence of≥60 min of MVPA≥1 days per week among adolescents globally,and to describe any relevant gender inequalities.Methods:We used representative datasets from 146 countries/territories collected between 2003 and 2019.MVPA was self-reported.Participants were grouped into younger(≤14 years old)and older(>14 years old)adolescents.Crude Poisson regression models were used to identify the relative differences in≥60 min of MVPA≥1 days per week between boys and girls,and random-effects meta-analysis models were used to identify the pooled estimates.Analyses were stratified by country and region.Results:Approximately 80%of both younger and older adolescents reported≥60 min of MVPA≥1 days per week.This prevalence was≥94%in Europe and Central Asia and North America,while the estimates for the other regions were<77%.The prevalence of≥60 min of MVPA≥1 days per week was higher among boys than girls,with the largest differences occurring among the oldest adolescents(Prevalence ratio_(≤14y)=1.04(95%confidence interval(95%CI)):1.03-1.04)vs.Prevalence ratio_(>14y)=1.09(95%CI:1.08-1.10)).Conclusion:Approximately 8 out of 10 adolescents reported accumulating≥60 min of MVPA≥1 days per week,with notable differences between regions.Gender differences were observed in several countries,especially among the oldest adolescents.Priorities for physical activity promotion among adolescents should include increasing access/opportunities for physical activity among those who do not achieve≥60 min of MVPA≥1 days per week and reducing gender inequalities.

Prospective associations between joint categories of physical activity and insomnia symptoms with onset of poor mental health in a population-based cohort

Background:Physical inactivity and insomnia symptoms are independently associated with increased risk of depression and anxiety;however,few studies jointly examine these risk factors.This study aimed to prospectively examine the joint association of physical activity(PA)and insomnia symptoms with onset of poor mental health in adults.Methods:Participants from the 2013 to 2018 annnual waves of the Household Income and Labour Dynamics in Australia panel study who had good mental health(Mental Health Inventory-5>54)in 2013,and who completed at least 1 follow-up survey(2014-2018),were included(n=10,977).Poor mental health(Mental Health Inventory-5≤54)was assessed annually.Baseline(2013)PA was classified as high/moderate/low,and insomnia symptoms(i.e.,trouble sleeping)were classified as no insomnia symptoms/insomnia symptoms,with 6 mutually exclusive PAinsomnia symptom groups derived.Associations of PA-insomnia symptom groups with onset of poor mental health were examined using discrete-time proportional-hazards logit-hazard models.Results:There were 2322 new cases of poor mental health(21.2%).Relative to the high PA/no insomnia symptoms group,there were higher odds(odds ratio and 95%confidence interval(95%CI))of poor mental health among the high PA/insomnia symptoms(OR=1.87,95%CI:1.57-2.23),moderate PA/insomnia symptoms(OR=1.93,95%CI:1.61-2.31),low PA/insomnia symptoms(OR=2.33,95%CI:1.96-2.78),and low PA/no insomnia symptoms(OR=1.14,95%CI:1.01-1.29)groups.Any level of PA combined with insomnia symptoms was associated with increased odds of poor mental health,with the odds increasing as PA decreased.Conclusion:The se findings highlight the potential benefit of interventions targeting both PA and insomnia symptoms for promoting mental health.

Recovery shape of physical activity after COVID-19 pandemic

Background:Since shutdowns associated with the coronavirus disease 2019 pandemic,there has been limited discourse on physical activity(PA)recovery(i.e.,the ability of individuals to resume PA at pre-pandemic levels),including recovery rate,speed of recovery,which individuals are able to return quickly,who is left behind,and what are the causes of those differences.This study aimed to estimate the level and shape of PA recovery rate in Thailand.Methods:This study employed 2 rounds(2020 and 2021)of Thailand's Surveillance on Physical Activity dataset for the analysis.Each round included over 6600 samples from individuals aged 18 years or older.PA was assessed subjectively.Recovery rate was calculated from the relative difference in the cumulative minutes of moderate-to-vigorous PA(MVPA)from 2 different periods.Results:The Thai population experienced a medium level of recession of PA(-26.1%)and a moderate level of recovery of PA(37.44%).PA recovery in the Thai population resembled an imperfect V shape,reflecting a sharp decline followed by an immediate upturn;still,recovered PA remained lower than pre-pandemic levels.The quickest recovery was found among older adults,whereas students,young adults,residents of Bangkok,the unemployed,and those who had a negative attitude toward PA experienced the highest recession of PA and were among the slowest to recover.Conclusion:The level of recovery of PA among Thai adults is largely determined by the preventive behaviors demonstrated by groups within the population who have a higher awareness of their health.The effect of the mandatory coronavirus disease 2019 containment measures on PA was temporary.However,the slower recovery rate of PA among some individuals was caused by a combination of restrictive measures and socioeconomic inequality,which required more time and effort to overcome.

Associations between aerobic and muscle-strengthening physical activity,sleep duration,and risk of all-cause mortality:A prospective cohort study of 282,473 U.S.adults

Purpose:To examine the joint associations between meeting guidelines for physical activity(PA)and sleep duration and all-cause mortality risk among adults.Methods:Participants were adults(n=282,473)aged 18-84 years who participated in the 2004-2014 U.S.National Health Interview Survey.Mortality status was ascertained using the National Death Index through December 2015.Self-reported PA(Active:meeting both aerobic(AER)and muscle-strengthening(MSA)guidelines,AER only(AER),MSA only(MSA),or not meeting either AER or MSA(Inactive))and sleep duration(Short,recommended(Rec),or Long)were classified according to guidelines,and 12 PA-sleep categories were derived.Adjusted hazard ratios and 95%confidence intervals(95%CIs)for all-cause mortality risk were estimated using Cox proportional hazards regression models.Results:A total of 282,473 participants(55%females)were included;18,793 deaths(6.7%)occurred over an average follow-up of 5.4 years.Relative to the Active-Rec group,all other PA-sleep groups were associated with increased mortality risk except for the Active-Short group(hazard ratio=1.08;95%CI:0.92-1.26).The combination of long sleep with either MSA or Inactive appeared to be synergistic.For a given sleep duration,mortality risk progressively increased among participants classified as AER,MSA,and Inactive.Within each activity level,the mortality risk was greatest among adults with long sleep.Conclusion:Relative to adults meeting guidelines for both PA and sleep duration,adults who failed to meet guidelines for both AER and muscle strengthening PA and who also failed to meet sleep duration guidelines had elevated all-cause mortality risks.These results support interventions targeting both PA and sleep duration to reduce mortality risk.

Physical activity in primary and secondary prevention of cardiovascular disease:Overview updated

Although the observed progress in the cardiovascular disease treatment, the incidence of new and recurrent coronary artery disease remains elevated and constitutes the leading cause of death in the developed countries. Three-quarters of deaths due to cardiovascular diseases could be prevented with adequate changes in lifestyle, including increased daily physical activity. New evidence confirms that there is an inverse dose-response relationship between physical activity and cardiovascular disease and mortality risk. However, participation in moderate to vigorous physical activity may not fully attenuate the independent effect of sedentary activities on increased risk for cardiovascular diseases. Physical activity also plays an important role in secondary prevention of cardiovascular diseases by reducing the impact of the disease, slowing its progress and preventing recurrence. Nonetheless, most of eligible cardiovascular patients still do not benefit from secondary prevention/cardiac rehabilitation programs. The present review draws attention to the importance of physical activity in the primary and secondary prevention of cardiovascular diseases. It also addresses the mechanisms by which physical activity and regular exercise can improve cardiovascular health and reduce the burden of the disease.

Does light-intensity physical activity moderate the relationship between sitting time and adiposity markers in adolescents?

Background:While the relationship between sedentary time and adiposity markers may be independent of moderate-to-vigorous intensity physical activity(MVPA) among adolescents,little is known about the role of light-intensity physical activity(LIPA) in this relationship.The aim of this cross-sectional study was to examine whether device-measured LIPA and MVPA moderate the associations between objectively measured sitting time and adiposity markers(body mass index(BMI)) and waist circumference(WC)) among adolescents.Methods:This study included accelerometer and inclinometer data obtained from 219 adolescents(age=14.9±1.6 years,mean± SD),collected during 2014 and 2015 in Melbourne,Australia.ActiGraph GT3 X accelerometers were used to determine time spent in total-LIPA(101 counts/min to 3.99 metabolic equivalents(METs)) was dichotomized into low-LIPA(101-799 counts/min) and high LIPA(800 counts/min to 3.99 METs),and MVPA(> 4 METs).The average time spent sitting was obtained from activPAL inclinometers.Anthropometric measures were assessed by trained staff.Interactions between sitting and total-LIPA,low-LIPA,high-LIPA,and MVPA on BMI z-score(zBMI) and WC z-score(zWC),respectively,were examined using linear regression,adjusting for age and sex;and moderation by total-LIPA,low-LIPA,high-LIPA,and MVPA were examined by adding interaction terms.Significant interaction effects were probed by comparing associations at the mean and at 1 SD below and above the mean.Results:Total-LIPA significantly moderated the association between sitting time and zBMI,and low-LIPA significantly moderated the association between sitting time and zBMI and zWC.No other associations were found for total-LIPA,high-LIPA,or MVPA.Specifically,at high levels of total-LIPA(+1 SD),there is a negative association between sitting time and zBMI.In addition,at high levels of low-LIPA(+1 SD),there is a negative association between sitting time and zBMI and zWC.Conclusion:Associations between sitting and adiposity depended on time spent in total-LIPA and low-LIPA,but not high-LIPA or MVPA.Results suggest that increasing time spent in LIP A may provide protection from the deleterious effects of sitting on adiposity markers among adolescents.Experimental evidence is needed to support these conclusions.

Is device-measured vigorous physical activity associated with health-related outcomes in children and adolescents? A systematic review and meta-analysis

Objective:This study sought to analyze the prospective association between vigorous-intensity physical activity(VPA)and health-related outcomes in children and adolescents.Methods:Studies reporting associations between device-measured VPA and health-related factors in children and adolescents aged 318 years were identified through database searches(MEDLINE,EMBASE,and SPORTDiscus).Correlation coefficients were pooled if outcomes were reported by at least 3 studies,using DerSimonian-Laird random effects models.Results:Data from 23 studies including 13,674 participants were pooled using random effects models.Significant associations were found between VPA at baseline and overall adiposity(r=0.09,95%confidence interval(95%CI):0.15 to0.03;p=0.002;I^(2)=89.8%),cardiometabolic risk score(r=0.13,95%CI:0.24 to0.02,p=0.020;I^(2)=69.6%),cardiorespiratory fitness(r=0.25,95%CI:0.150.35;p<0.001;I^(2)=57.2%),and total body bone mineral density(r=0.16,95%CI:0.06 to 0.25;p=0.001;I^(2)=0%).Conclusion:VPA seems to be negatively related to adiposity and cardiometabolic risk score and positively related to cardiorespiratory fitness and total body bone mineral density among children and adolescents at follow-up.Therefore,our findings support the need to strengthen physical activity recommendations regarding VPA due to its health benefits in children and adolescents.

Activity-related typologies and longitudinal change in physical activity and sedentary time in children and adolescents:The UP&DOWN Study

Background:Children and adolescents can be distinguished by different typologies(clusters) of physical activity and sedentary behavior.How physical activity and sedentary behaviors change over time within different typologies is not known.This study examined longitudinal changes in physical activity and sedentary time among children and adolescents with different baseline typologies of activity-related behavior.Methods:In this longitudinal study(3 annual time points) of children(n=600,age=9.2±0.4 years(mean±SD),50.3% girls) and adolescents(n=1037,age=13.6±1.7 years,48.4% girls),participants were recruited in Spain in 2011-2012.Latent class analyses identified typologies based on self-reported screen,educational,social and relaxing sedentary behaviors,active travel,muscle strengthening activity,and sport at baseline.Within each typology,linear mixed growth models explored longitudinal changes in accelerometer-derived moderate-to-vigorous physical activity and sedentary time,as well as time by class interactions.Results:Three typologies were identified among children( "social screenies",12.8%;"exercisers",61.5%;and "non-sporty active commuters",25.7%) and among adolescents "active screenies",43.5%;"active academics",35.0%;and "non-sporty active commuters",21.5%) at baseline.Sedentary time increased within each typology among children and adolescents,with no significant differences between typologies.No changes in physical activity were found in any typology among children.In adolescents,physical activity declined within all typologies,with "non-sporty active commuters" declining significantly more than "active screenies" over 3 years.Conclusion:These results support the need for interveation to promote physical activity and prevent increases in sedentary time during childhood and adolescence.Adolescents characterized as "non-sporty active commuters" may require specific interventions to maintain their physical activity over time.

Acceptability,usefulness,and satisfaction with a web-based video-tailored physical activity intervention:The TaylorActive randomized controlled trial

Purpose:This study aimed to examine the usage,acceptability,usability,perceived usefulness,and satisfaction of a web-based video-tailored physical activity(PA)intervention(TaylorActive)in adults.Methods:In 2013-2014,501 Australian adults aged 18+years were randomized into a video-tailored intervention,text-tailored intervention,or control group.Over 3 months,the intervention groups received access to 8 sessions of personally tailored PA advice delivered via the TaylorActive website.Only the delivery method differed between the intervention groups:video-tailored vs.text-tailored.Google Analytics and telephone surveys conducted at post intervention(3 months)were used to assess intervention usage,acceptability,usability,perceived usefulness,and satisfaction.Quantitative and qualitative process data were analyzed using descriptive statistics and thematic content analysis.Results:Of 501 recruited adults,259 completed the 3-month post-intervention survey(52%retention).Overall,usage of the TaylorActive website with respect to number of website visits,intervention sessions,and action plans completed was modest in both the video-tailored(7.6士7.2 visits,mean±SD)and text-tailored(7.3±5.4 visits)groups with no significant between-group differences.The majority of participants in all groups used the TaylorActive website less than once in 2 weeks(66.7%video-tailored,62.7%text-tailored,87.5%control;p<0.001).Acceptability was rated mostly high in all groups and in some instances,significantly higher in the intervention groups compared to the control group(p<0.010).Usability was also rated high;mean Systems Usability Scores were 77.3(video-tailored),75.7(text-tailored),and 74.1(control)with no significant between-group differences.Perceived usefulness of the TaylorActive intervention was low,though mostly rated higher in the intervention groups compared to the control group(p<0.010).Satisfaction with the TaylorActive website was mixed.Participants in both intervention groups liked its ease of use,personalized feedback,and tracking of progress,but also found completing action plans and survey questions for each session repetitive and tedious.Conclusion:Providing personally tailored PA advice on its own(through either video or text)is likely insufficient to ensure good retention,usage,perceived usefulness,and satisfaction with a web-based PA intervention.Strategies to address this may include the incorporation of additional intervention components such as activity trackers,social interactions,gamification,as well as the use of advanced artificial intelligence and machine learning technologies to allow more personalized dialogue with participants.

Responses to oral glucose challenge differ by physical activity volume and intensity: A pilot study

Background:One-hour postprandial hyperglycemia is associated with increased risk of type 2 diabetes and cardiovascular disease.Physical activity(PA)has short-term beneficial effects on post-meal glucose response.This study compared the oral glucose tolerance test results of 3 groups of people with habitually different levels of PA.Methods:Thirty-one adults without diabetes(age 25.9±6.6 years;body mass index 23.8±3.8 kg/m^2;mean±SD)were recruited and divided into 3 groups based on self-reported PA volume and intensity:low activity<30 min/day of moderate-intensity activity(n=11),moderately active≥30 min/day of moderate-intensity PA(n=10),and very active≥60 min/day of PA at high intensity(n=10).Participants completed an oral glucose tolerance test(50 g glucose)with capillary blood samples obtained at baseline,15 min,30 min,45 min,60 min,90 min,and 120 min post-ingestion.Results:There were no significant differences between groups for age or body fat percentage or glycated hemoglobin(p>0.05).The groups were significantly different in terms of baseline glucose level(p=0.003)and,marginally,for gender(p=0.053)and BMI(p=0.050).There was a statistically significant effect of PA on the 1-h postprandial glucose results(p=0.029),with differences between very active and low activity groups(p=0.008)but not between the moderately active and low activity groups(p=0.360),even when baseline glucose level and gender differences were accounted for.For incremental area under the curve there was no significant effect of activity group once gender and body fat percentage had been accounted for(p=0.401).Those in the low activity group took 15 min longer to reach peak glucose level than those in the very active group(p=0.012).Conclusion:The results suggest that high levels of PA have a beneficial effect on postprandial blood glucose profiles when compared to low and moderate levels of activity.

The effects of the COVID-19 pandemic on the physical activity of the Thai population: Evidence from Thailand’s Surveillance on Physical Activity 2020

Background:The coronavirus disease 2019(COVID-19)pandemic has undoubtedly disrupted the physical activity(PA)of the Thai population.This study examined the effect of the COVID-19 pandemic on moderate-to-vigorous PA(MVPA)of Thai adults and assessed the effects of the national curfew policy and health-promotion campaigns on influencing PA during the pandemic.Methods:Thailand’s Surveillance on Physical Activity(SPA)2019 and 2020 datasets were employed to compare the PA level of Thai adults aged 1864 years before and during the COVID-19 pandemic.Samples of 4460 respondents from SPA 2019 and 4482 respondents from SPA 2020 were included in the analysis.Global Physical Activity Questionnaires(Version 2.0),were used to measure PA in both periods.Sufficient MVPA for adults was defined based on the recommendation of 75 min of vigorous PA or a combination of 150 min of MVPA per week.Results:The proportion of Thai adults who had sufficient MVPA declined from 74.6%before the pandemic to 54.7%during the pandemic,and that decline was accompanied by a reduction in the cumulative minutes of MVPA from 580 min to 420 min.During the COVID-19 pandemic,male and middle-aged individuals were 1.3 times and 1.2 times more likely to have sufficient MVPA,respectively.Those who were unemployed,resided in an urban area,and/or had chronic disease(s)were 27%,13%,and 27%less likely to meet the recommended level of PA during the pandemic,respectively.Those who were exposed to the Fit from Home campaign were 1.5 times more likely to have sufficient MVPA.Conclusion:The pandemic measures imposed by the government have reduced the cumulative min of work-related PA,transportation PA,and recreational PA and have slowed Thailand’s progress toward its PA goals.Although the Fit from Home campaign has probably contributed to a slight increase in MVPA,it will take some time for Thais to return to the pre-COVID-19 level of PA.Health promotion messages need to be continuously delivered to reduce irrational fear of infection and to boost the PA level of the Thai population as a health-promoting intervention.

Cultural Adaptation and Psychometric Evaluation of Physical Activity Social Cognitive Scales for Brazilian Adolescents

SCT （social cognitive theory） provides a useful framework to explain why people acquire and maintain PA （physical activity） behaviors among adolescents. This study aimed to adapt modernized Australian social cognitive scales of PA to the Portuguese language and evaluate their factorial and convergent validity and reliability. The adapted scales were tested in an adolescent sample from low-income communities in the city of Sao Paulo, Brazil （n = 173; 56.1% male）. Confirmatory factor analysis was employed to examine model-fit for each scale. The scales were assessed against self-report measures of moderate-to-vigorous physical activity for convergent validity. Reliability properties （ICC （lntra class confidence） and Cronbach＇s Alpha） were also determined. Each social cognitive scale represented a statistically sound measure： fit indices indicated each model to be adequate-to-exact fit to the data; significant correlations between most scales and either light, moderate or vigorous intensity PA behavior demonstrated good convergent validity; internal consistency was acceptable-to-good （α = 0.51-0.80）; rank order repeatability was acceptable-to-strong （ICC = 0.62-0.92）. Adapted social cognitive scales for physical activity for use among adolescents in the Brazilian context showed acceptable reliability and validity properties and may be useful to identify potential social cognitive correlates of PA, mediators of PA behavior change and the testing of theoretical models of SCT.

Why have youth physical activity trends flatlined in the last decade? Opinion piece on “Global trends in insufficient physical activity among adolescents: a pooled analysis of 298 population-based surveys with 1.6 million participants” by Guthold et al.

1.No global progress on youth physical activity prevalenceTagedEnd TagedPDespite hundreds of intervention studies over decennia that have been dedicated to developing and testing programs and strategies to promote physical activity(PA)in adolescents,14 global inactivity levels remain persistently high.Based on self-report data from 1.6 million schoolgoing adolescents from 146 countries,Guthold et al.5 confirmed previous urgent calls to get adolescents more active.Researchers from the World Health Organization(WHO)recently published global prevalence rates and the first ever global time trends for insufficient PA in youth.They reported that more than 80%of school-going adolescents globally did not meet the current recommendations of at least 1 h of PA per day.

Effect of different intensities of physical activity on cardiometabolic markers and vascular and cardiac function in adult rats fed with a high-fat high-carbohydrate diet

Background: Physical activity(PA) and diet are 2 lifestyle factors that affect cardiometabolic risk. However, data on how a high-fat highcarbohydrate(HFHC) diet influences the effect of different intensities of PA on cardiometabolic health and cardiovascular function in a controlled setting are yet to be fully established. This study investigated the effect of sedentary behavior, light-intensity training(LIT), and high-intensity interval training(HIIT) on cardiometabolic markers and vascular and cardiac function in HFHC-fed adult rats.Methods: Twelve-week-old Wistar rats were randomly allocated to 4 groups(12 rats/group): control(CTL), sedentary(SED), LIT, and HIIT.Biometric indices, glucose and lipid control, inflammatory and oxidative stress markers, vascular reactivity, and cardiac electrophysiology of the experimental groups were examined after 12 weeks of HFHC-diet feeding and PA interventions.Results: The SED group had slower cardiac conduction(p = 0.0426) and greater thoracic aortic contractile responses(p < 0.05) compared with the CTL group. The LIT group showed improved cardiac conduction compared with the SED group(p = 0.0003), and the HIIT group showed decreased mesenteric artery contractile responses compared with all other groups and improved endothelium-dependent mesenteric artery relaxation compared with the LIT group(both p < 0.05). The LIT and HIIT groups had lower visceral(p = 0.0057 for LIT, p = 0.0120 for HIIT)and epididymal fat(p < 0.0001 for LIT, p = 0.0002 for HIIT) compared with the CTL group.Conclusion: LIT induced positive adaptations on fat accumulation and cardiac conduction, and HIIT induced a positive effect on fat accumulation,mesenteric artery contraction, and endothelium-dependent relaxation. No other differences were observed between groups. These findings suggest that few positive health effects can be achieved through LIT and HIIT when consuming a chronic and sustained HFHC diet.

Longitudinal associations of physical activity and pubertal development with academic achievement in adolescents

Objective: We sought to investigate the longitudinal associations of moderate-to-vigorous physical activity(MVPA) and pubertal development with academic achievement in adolescents.Methods: A total of 635 adolescents(283 boys, 352 girls) aged 11-13 years participated in the study. MVPA was assessed by the Health Behaviour in School-aged Children study questionnaire, and pubertal development was assessed by the Pubertal Development Scale at beginning of the 6 th grade(baseline) and end of the 7 th grade(follow-up). Grade point average(GPA) at the end of Grades 5 and 7 was computed from data acquired from the school registers. The data were analyzed using linear regression and analyses of covariance.Results: In boys, MVPA was positively associated with GPA at baseline after adjustment for age(b = 0.144, 95% confidence interval(CI):0.028-0.260, p = 0.028). In girls, the Pubertal Development Scale was positively associated with GPA at baseline(b = 0.104, 95%CI: -0.004 to0.211, p = 0.058) and follow-up(b = 0.104, 95%CI: -0.002 to 0.211, p = 0.055) after adjustment for age, and these associations strengthened after further adjustment for MVPA(p < 0.05). Adolescents who were inactive at baseline or at baseline and follow-up had lower GPA during followup than their continuously highly active peers(mean difference = -0.301, 95%CI: -0.543 to -0.058, p = 0.009) and all other adolescents(mean difference = -0.247, 95%CI: -0.475 to -0.019, p = 0.029). These differences were greater in girls than in boys.Conclusion: Lower levels of MVPA were associated with lower GPA in boys at baseline. Girls who were continuously inactive had lower GPA over the follow-up period than those who were continuously active. Finally, earlier pubertal development was associated with better academic achievement in girls.

What is driving gender inequalities in physical activity among adolescents?

In most countries around the globe,adolescent girls are less physically active than boys.However,the majority of studies have been conducted in high-income countries,while there is less evidence from low-and middle-income countries.1 The reasons for this gender difference in physical activity(PA)participation are poorly understood.A recently published article by Ricardo et al.2 on gender inequalities in adolescent PA from 64 global south countries seeks to close this knowledge gap.