A physically active lifestyle is related to a lower level of skin autofluorescence in a large population with chronic-disease (LifeLines cohort)

Background:Physical activity(PA)has substantial health benefits and is important in combatting chronic diseases,which have been associated with elevated levels of advanced glycation endproducts(AGEs).AGEs play a role in the aging process,and an association between PA and AGEs has been reported.We aimed to investigate the relationship between PA and AGE accumulation in a general population and in a population with chronic diseases.Methods:This large cross-sectional population study used data from adult participants in the LifeLines project,with participant information drawn from the LifeLines database as well data from patients with diabetes mellitus or renal and/or cardiovascular diseases.Tissue AGE accumulation was assessed non-invasively by skin-autofluorescence(SAF)using an AGE reader(DiagnOptics Technologies BV,Groningen,the Netherlands).PA was assessed using the short questionnaire to assess health-enhancing physical activity(SQUASH).Multivariate linear regression analyses were adjusted for age,body mass index,sex,and smoking status.Results:Data from 63,452 participants(general population n=59,177,chronic disease n=4275)were analyzed.The general population was significantly younger(43.58±11.77 years,mean±SD)and had significantly lower SAF(1.90±0.42 arbitrary units(AU))compared to the population with chronic disease(age:55.51±12.07 years;SAF:2.27±0.51 AU).In the group with chronic disease,more hours of moderate to vigorous physical activities per week were associated with lower SAF(β=-0.002,95%confidence interval(95%CI):-0.002 to-0.001).For the general population,there was no association between hours of moderate to vigorous activity and SAF(β=3.2×10^-5,95%CI:0.000-0.001,p=0.742).However,there was an association in the general population between total hours of PA per week and SAF(β=4.2×10^-4,95%CI:0.000-0.001,p<0.001),but this association was not found in the chronic disease population(β=-3.2×10^-4,95%CI:-0.001 to 0.000,p=0.347).Conclusion:Our study demonstrates that an inverse relationship exists between PA and AGE accumulation in the population with chronic disease.More hours of moderate to vigorous activity is associated a significantly decreased SAF.More PA is associated a lower SAF,even after for the established predictors(age,body mass index,smoking status,and sex).Our findings could help to promote health and prolong longevity.     

Bidirectional relationships of physical activity and gross motor skills before and after summer break: Application of a cross-lagged panel model

Background:Gross motor skills are postulated to have a bidirectional relationship with physical activity(PA);however,no study has tested this relationship before and after a summer break.The purpose of this study was to examine the bidirectional relationships between school PA and gross motor skills in children before and after a summer break.Methods:Participants were a sample of 440 children recruited from 3 low-income schools(age=8.9±1.2 years,mean±SD).PA was assessed as average school-day step counts using Yamax DigiWalker pedometers(Yamasa Tokei Keiki,Tokyo,Japan)worn for 5 consecutive school days.Gross motor skills were assessed using the Test for Gross Motor Development,3 rd edition.Data were collected at 2 timepoints:at the end of spring semester(T1)and at the beginning of the subsequent fall semester(T2).An age-and body mass index-adjusted cross-lagged model was employed to relate T1 school step counts with T2 gross motor skills and T1 gross motor skills with T2 school step counts.Results:T1 gross motor skills significantly predicted T2 school step counts(β=0.24,95%confidence interval(95%CI):0.08-0.40,p=0.003);however,Tl school step counts did not predict T2 gross motor skills(β=0.04,95%CI:-0.06 to 0.14,p=0.445).The model explained 35.4%and 15.9%of the variances of T2 gross motor skills and T2 school step counts,respectively.Additional analyses indicated that these relationships were driven primarily by ball skills.Conclusion:The relationship between gross motor skills and school PA was not bidirectional;however,higher gross motor skills,specifically ball skills,predicted higher school PA after a 3-month summer break.     

The effects of plyometric jump training on lower-limb stiffness in healthy individuals: A meta-analytical comparison

PurposeThis study aimed to examine the effects of plyometric jump training (PJT) on lower-limb stiffness.MethodsSystematic searches were conducted in PubMed, Web of Science, and Scopus. Study participants included healthy males and females who undertook a PJT programme isolated from any other training type.ResultsThere was a small effect size (ES) of PJT on lower-limb stiffness (ES = 0.33, 95% confidence interval (95%CI): 0.07–0.60, z = 2.47, p = 0.01). Untrained individuals exhibited a larger ES (ES = 0.46, 95%CI: 0.08–0.84, p = 0.02) than trained individuals (ES = 0.15, 95%CI: ‒0.23 to 0.53, p = 0.45). Interventions lasting a greater number of weeks (>7 weeks) had a larger ES (ES = 0.47, 95%CI: 0.06–0.88, p = 0.03) than those lasting fewer weeks (ES = 0.22, 95%CI: ‒0.12 to 0.55, p = 0.20). Programmes with ≤2 sessions per week exhibited a larger ES (ES = 0.39, 95%CI: 0.01–0.77, p = 0.04) than programmes that incorporated >2 sessions per week (ES = 0.20, 95%CI: –0.10 to 0.50, p = 0.18). Programmes with <250 jumps per week (ES = 0.50, 95%CI: 0.02–0.97, p = 0.04) showed a larger effect than programmes with 250–500 jumps per week (ES = 0.36, 95%CI: 0.00–0.72, p = 0.05). Programmes with >500 jumps per week had negative effects (ES = –0.22, 95%CI: –1.10 to 0.67, p = 0.63). Programmes with >7.5 jumps per set showed larger effect sizes (ES = 0.55, 95%CI: 0.02–1.08, p = 0.04) than those with <7.5 jumps per set (ES = 0.32, 95%CI: 0.01–0.62, p = 0.04).ConclusionPJT enhances lower-body stiffness, which can be optimised with lower volumes (<250 jumps per week) over a relatively long period of time (>7 weeks).     

Factors that affect heart rate variability following acute resistance exercise: A systematic review and meta-analysis

BackgroundThere is controversial evidence regarding the effect of acute resistance exercise (ARE) on heart rate variability (HRV) parameters, which indicates the activities of the cardiac autonomic nervous system. The aim of this study was to perform a systematic review and meta-analysis of the literature on the effect of ARE on HRV parameters and identify its possible moderating factors.MethodsThe PubMed–Medline, Web of Science, SPORTDiscus, and Cochrane Library databases were searched. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) declaration was followed, and the methodological quality of the studies was evaluated. The level of significance was set at p ≤ 0.05. Twenty-six studies met the inclusion criteria. Main effect analyses between pre- and post-test interventions demonstrated an increase in normalized units low frequency (p < 0.001; standardized mean difference (SMD) = 0.78; 95% confidence interval (95%CI): 0.46?1.11) and low frequency/high frequency ratio (p < 0.001; SMD = 0.82; 95%CI: 0.64?0.99) and a decrease in standard deviation of the normal-to-normal (NN) interval (p < 0.001; SMD = –0.58; 95%CI: –0.85 to –0.30), root mean square of the successive differences (p < 0.001; SMD = –1.01; 95%CI: –1.29 to –0.74), and normalized units high frequency (p < 0.001; SMD: –1.08; 95%CI: –1.43 to –0.73) following ARE in healthy individuals range: 15 ± 1 to 48 ± 2 years; mean ± SD).ResultsThere were differences between the subgroups in the number of sets used in an exercise (p = 0.05) for root mean square of the successive differences, as well as for exercise intensity (p = 0.01) and rest between sets (p = 0.05) for normalized units high frequency. Interestingly, there were differences between the subgroups in training volume for root mean square of the successive differences (p = 0.01), normalized units high frequency (p = 0.003) and normalized units low frequency (p = 0.02).ConclusionOverall, there was a withdrawal of cardiac parasympathetic and activation of cardiac sympathetic modulations following ARE, and these changes were greater with higher training volume ～30 min after ARE in healthy individuals. Furthermore, the number of sets, intensity, and rest between sets affected HRV parameters. However, gender, body mass index, and training status did not influence the changes in HRV parameters as a response to ARE.     

Projecting the impact of the coronavirus disease-2019 pandemic on childhood obesity in the United States: A microsimulation model

PurposeThe coronavirus disease-2019 (COVID-19) pandemic in the United States led to nationwide stay-at-home orders and school closures. Declines in energy expenditure resulting from canceled physical education classes and reduced physical activity may elevate childhood obesity risk. This study estimated the impact of COVID-19 on childhood obesity.MethodsA microsimulation model simulated the trajectory of a nationally representative kindergarten cohort's body mass index z-scores and childhood obesity prevalence from April 2020 to March 2021 under the control scenario without COVID-19 and under the 4 alternative scenarios with COVID-19—Scenario 1: 2-month nationwide school closure in April and May 2020; Scenario 2: Scenario 1 followed by a 10% reduction in daily physical activity in the summer from June to August; Scenario 3: Scenario 2 followed by 2-month school closure in September and October; and Scenario 4: Scenario 3 followed by an additional 2-month school closure in November and December.ResultsRelative to the control scenario without COVID-19, Scenarios 1, 2, 3, and 4 were associated with an increase in the mean body mass index z-scores by 0.056 (95% confidence interval (95%CI): 0.055–0.056), 0.084 (95%CI: 0.084–0.085), 0.141 (95%CI: 0.140–0.142), and 0.198 (95%CI: 0.197–0.199), respectively, and an increase in childhood obesity prevalence by 0.640 (95%CI: 0.515–0.765), 0.972 (95%CI: 0.819–1.126), 1.676 (95%CI: 1.475–1.877), and 2.373 (95%CI: 2.135–2.612) percentage points, respectively. Compared to girls and non-Hispanic whites and Asians, the impact of COVID-19 on childhood obesity was modestly larger among boys and non-Hispanic blacks and Hispanics, respectively.ConclusionPublic health interventions are urgently called to promote an active lifestyle and engagement in physical activity among children to mitigate the adverse impact of COVID-19 on unhealthy weight gains and childhood obesity.     

The potential of a year-round school calendar for maintaining children's weight status and fitness: Preliminary outcomes from a natural experiment

PurposeTo evaluate the potential of a year-round school calendar (180-day school year distributed across 12 months) as an intervention compared to a traditional school calendar (180-day school year distributed across 9 months) for mitigating children's weight gain and fitness loss via a natural experiment.MethodsHeight, weight, and cardiorespiratory fitness (CRF) (i.e., Fitnessgram Progressive Aerobic Cardiovascular Endurance Run) were measured in children (5–12 years old) in 3 schools (2 traditional, 1 year-round, n = 990 students, age = 8.6 ± 2.4 years, 53.1% male, 68.9% African American) from 1 school district. Structure (represented by the presence of a school day) was the independent variable. Changes in body mass index (BMI), age- and sex-specific BMI z-scores (zBMI), BMI percentile, percent of overweight or obese children, and CRF (Progressive Aerobic Cardiovascular Endurance Run laps completed) were assessed for summer 2017 (May–August 2017), school year 2017/2018 (August 2017–May 2018), and summer 2018 (May–August 2018). Primary analyses examined the overall change in weight and CRF from summer 2017 until summer 2018 via multilevel mixed effects regression, with group (traditional vs. year-round calendar), time, and a group-by-time interaction as the independent variables. Secondary regression analyses estimated differences in change within and between groups during each time period, separately.ResultsYear-round students gained less BMI (difference in ∆ = –0.44, 95% confidence interval (CI): –0.67 to –0.03) and less CRF (difference in ∆ = –1.92, 95%CI: –3.56 to –0.28) than students attending a traditional school overall. Compared with traditional students, during both summers, year-round students gained less BMI (summer 2017 difference in ∆ = –0.15, 95%CI: –0.21 to –0.08; summer 2018 difference in ∆ = –0.16, 95%CI: –0.24 to –0.07) and zBMI (summer 2017 difference in ∆ = –0.032, 95%CI: –0.050 to –0.010; summer 2018 difference in ∆ = –0.033, 95%CI: –0.056 to –0.009), and increased CRF (summer 2017 difference in ∆ = 0.40, 95%CI: 0.02–0.85; summer 2018 difference in ∆ = 0.23, 95%CI: –0.25 to 0.74). However, the opposite was observed for the school year, with traditional students gaining less BMI and zBMI and increasing CRF compared with year-round students (difference in BMI ∆ = 0.05, 95%CI: 0.03–0.07; difference in zBMI ∆ = 0.012, 95%CI: 0.005–0.019; difference in Progressive Aerobic Cardiovascular Endurance Run laps ∆ = –0.43, 95%CI: –0.58 to –0.28).ConclusionThe year-round school calendar had a small beneficial impact on children's weight status but not CRF. It is unclear if this benefit to children's weight would be maintained because gains made in the summer were largely erased during the school year. Trajectories of weight and CRF gain/loss were consistent with the structured days hypothesis.     

Adolescents’ perspectives on a school-based physical activity intervention: A mixed method study

PurposeTo examine adolescent experiences and perspectives of the GoActive intervention (ISRCTN31583496) using mixed methods process evaluation to determine satisfaction with intervention components and interpret adolescents’ experiences of the intervention process in order to provide insights for future intervention design.MethodsParticipants (n = 1542; 13.2 ± 0.4 years, mean ± SD) provided questionnaire data at baseline (shyness, activity level) and post-intervention (intervention acceptability, satisfaction with components). Between-group differences (boys vs. girls and shy/inactive vs. others) were tested with linear regression models, accounting for school clustering. Data from 16 individual interviews (shy/inactive) and 11 focus groups with 48 participants (mean = 4; range 2–7) were thematically coded. Qualitative and quantitative data were merged in an integrative mixed methods convergence matrix, which denoted convergence and dissonance across datasets.ResultsEffect sizes for quantitative results were small and may not represent substantial between-group differences. Boys (vs. girls) preferred class-based sessions (β = 0.2, 95% confidence interval (CI): 0.1–0.3); qualitative data suggested that this was because boys preferred competition, which was supported quantitatively (β = 0.2, 95%CI: 0.1–0.3). Shy/inactive students did not enjoy the competition (β = –0.3, 95%CI: –0.5 to –0.1). Boys enjoyed trying new activities more (β = 0.1, 95%CI: 0.1–0.2); qualitative data indicated a desire to try new activities across all subgroups but identified barriers to choosing unfamiliar activities with self-imposed choice restriction leading to boredom. Qualitative data highlighted critique of mentorship; adolescents liked the idea, but older mentors did not meet expectations.ConclusionWe interpreted adolescent perspectives of intervention components and implementation to provide insights into future complex interventions aimed at increasing young people's physical activity in school-based settings. The intervention component mentorship was liked in principle, but implementation issues undesirably impacted satisfaction; competition was disliked by girls and shy/inactive students. The results highlight the importance of considering gender differences in preference of competition and extensive mentorship training.     

Environmental correlates of sedentary behaviors and physical activity in Chinese preschool children: A cross-sectional study

ObjectiveThis cross-sectional study examined environmental correlates of sedentary behavior (SB) and physical activity (PA) in preschool children in the urban area of Tianjin, China.MethodsData were collected from the Physical Activity and Health in Tianjin Chinese Children study, involving healthy children 3–6 years old and their families. In all children (n = 980), leisure-time SB (LTSB) and leisure-time PA (LTPA) were reported in min/day by parents. In a subgroup (n = 134), overall sedentary time, light PA, and moderate-to-vigorous PA (MVPA) were objectively measured using ActiGraph accelerometry (≥3 days, ≥10 h/day). Environmental correlates were collected using a questionnaire that included home and neighborhood characteristics (e.g., traffic safety, presence of physical activity facilities) and children's behaviors. Potential correlates were identified using linear regression analysis.ResultsMultiple linear regression analysis showed that “having grandparents as primary caregivers” (βs and 95% confidence intervals (95%CIs) for overall sedentary time: 29.7 (2.1–57.2); LTSB (ln): 0.19 (0.11–0.28)) and “having a television (for LTSB (ln): 0.13 (0.00–0.25)) or computer (for LTSB (ln): 0.13 (0.03–0.23)) in the child's bedroom” were both associated with higher SB. Furthermore, “having grandparents as primary caregivers” was associated with less MVPA (β (95%CI): ?7.6 (?14.1 to ?1.2)), and “active commuting to school by walking” correlated with more MVPA (β (95%CI): 9.8 (2.2–17.4)). The path model showed that “more neighborhood PA facilities close to home” was indirectly related to higher LTPA (ln), which was partly mediated by “outdoor play” (path coefficients (95%CI): 0.005 (0.002–0.008)) and “going to these facilities more often” (path coefficients (95%CI): 0.013 (0.008–0.018)). Traffic safety was not a correlate.ConclusionFamily structure and media exposure in the home maybe important factors in shaping preschoolers’ PA patterns. Built environmental correlates could indirectly influence preschoolers’ LTPA through parental help with engaging in active behaviors.     

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.     

Effects of resistance training performed to repetition failure or non-failure on muscular strength and hypertrophy: A systematic review and meta-analysis

Purpose:We aimed to perform a systematic review and meta-analysis of the effects of training to muscle failure or non-failure on muscular strength and hypertrophy.Methods:Meta-analyses of effect sizes(ESs)explored the effects of training to failure vs.non-failure on strength and hypertrophy.Subgroup meta-analyses explored potential moderating effects of variables such as training status(trained vs.untrained),training volume(volume equated vs.volume non-equated),body region(upper vs.lower),exercise selection(multi-vs.single-joint exercises(only for strength)),and study design(independent vs.dependent groups).Results:Fifteen studies were included in the review.All studies included young adults as participants.Meta-analysis indicated no significant difference between the training conditions for muscular strength(ES=-0.09,95%confidence interval(95%CI):-0.22 to 0.05)and for hypertrophy(ES=0.22,95%CI:-0.11 to 0.55).Subgroup analyses that stratified the studies according to body region,exercise selection,or study design showed no significant differences between training conditions.In studies that did not equate training volume between the groups,the analysis showed significant favoring of non-failure training on strength gains(ES=-0.32,95%CI:-0.57 to-0.07).In the subgroup analysis for resistance-trained individuals,the analysis showed a significant effect of training to failure for muscle hypertrophy(ES=0.15,95%CI:0.03-0.26).Conclusion:Training to muscle failure does not seem to be required for gains in strength and muscle size.However,training in this manner does not seem to have detrimental effects on these adaptations,either.More studies should be conducted among older adults and highly trained individuals to improve the generalizability of these findings.     

Prevalence of meeting 24-Hour Movement Guidelines from pre-school to adolescence: A systematic review and meta-analysis including 387,437 participants and 23 countries

BackgroundMeeting the 24-Hour Movement Guidelines (physical activity, screen time, and sleep duration) has been associated with positive health indicators. However, there are no previous meta-analyses that have examined the overall adherence to the 24-Hour Movement Guidelines from pre-school to adolescence across the world. Therefore, the main purpose of this systematic review and meta-analysis was to examine the overall (non)adherence to the 24-Hour Movement Guidelines among preschoolers, children, and adolescents worldwide.MethodsFour electronic databases (MEDLINE, Scopus, Web of Science, and Cochrane Database of Systematic Reviews) were searched for quantitative studies published in Spanish and English between January 2016 and May 2021. Studies that were conducted with apparently healthy participants and reported the overall (non)adherence to the 24-Hour Movement Guidelines in preschoolers and/or children and/or adolescents were included.ResultsSixty-three studies comprising 387,437 individuals (51% girls) aged 3–18 years from 23 countries were included. Overall, 7.12% (95% confidence interval (95%CI): 6.45%–7.78%) of youth met all three 24-Hour Movement Guidelines, and 19.21% (95%CI: 16.73%–21.69%) met none of the 3 recommendations. Concerning sex, adherence to all recommendations was significantly lower in girls (3.75%, 95%CI: 3.23%–4.27%) than in boys (6.89%, 95%CI: 5.89%–7.89%) (p < 0.001). However, there were no sex differences regarding adherence to any of the 3 individual recommendations (girls, 15.66%, 95%CI: 8.40%–22.92%; boys, 12.95%, 95%CI: 6.57%–19.33%). In terms of age group, adherence to the 3 recommendations was 11.26% (95%CI: 8.68%–13.84%), 10.31% (95%CI: 7.49%–13.12%), and 2.68% (95%CI: 1.78%–3.58%) in preschoolers, children, and adolescents, respectively. Conversely, 8.81% (95%CI: 5.97%–11.64%) of preschoolers, 15.57% (95%CI: 11.60%–19.54%) of children, and 28.59% (95%CI: 22.42%–34.75%) of adolescents did not meet any of the recommendations. South America was the region with the lowest adherence (all: 2.93%; none: 31.72%). Overall adherence to the 24-Hour Movement Guidelines was positively related to country Human Development Index (β = –0.37, 95%CI: –0.65 to –0.09; p = 0.010).ConclusionMost young people fail to meet the three 24-Hour Movement Guidelines, particularly adolescents, girls, and those who are from countries with a lower Human Development Index. Moreover, 1 in 5 young people did not meet any of these recommendations. Therefore, these results highlight the need to develop age- and sex-specific strategies to promote these movement behaviors from the early stages of life.     

Long-term exposure to fine particulate matter modifies the association between physical activity and hypertension incidence

BackgroundThe trade-off between the benefits of regular physical activity (PA) and the potentially detrimental effects of augmented exposure to air pollution in highly polluted regions remains unclear. This study aimed to examine whether ambient fine particulate matter (PM_2.5) exposure modified the impacts of PA volume and intensity on hypertension risk.MethodsWe included 54,797 participants without hypertension at baseline in a nationwide cohort of the Prediction for Atherosclerotic Cardiovascular Disease Risk in China (China-PAR) project. PA volume and intensity were assessed by questionnaire, and high-resolution (1 km ×1 km) PM_2.5 estimates were generated using a satellite-based model.ResultsDuring 413,516 person-years of follow-up, 12,100 incident hypertension cases were identified. PM_2.5 significantly modified the relationship between PA and hypertension incidence (p_interaction < 0.001). Increased PA volume was negatively associated with incident hypertension in the low PM_2.5 stratum (<59.8 μg/m³, p_trend < 0.001), with a hazard ratio of 0.81 (95% confidence interval (95%CI): 0.74–0.88) when comparing the fourth with the first quartile of PA volume. However, the health benefits were not observed in the high PM_2.5 stratum (≥59.8 μg/m³, p_trend = 0.370). Moreover, compared with light PA intensity, vigorous intensity was related to a 20% (95%CI: 9%–29%) decreased risk of hypertension for participants exposed to low PM_2.5, but a 17% (95%CI: 4%–33%) increased risk for those with high PM_2.5 levels.ConclusionPA was associated with a reduced risk of hypertension only among participants with low PM_2.5 exposure. Our findings recommended regular PA to prevent hypertension in less polluted regions and reinforced the importance of air quality improvement.     

Effects of a remote,YouTube-delivered exercise intervention on young adults’physical activity,sedentary behavior,and sleep during the COVID-19 pandemic:Randomized controlled trial

Background:Public health guidelines have called for innovative and flexible physical activity(PA)intervention strategies to promote PA and health amid the coronavirus disease 2019(COVID-19)pandemic.Therefore,this study’s purpose was to examine the effects of a home-based,YouTube-delivered PA intervention grounded in self-determination theory on young adults’free-living PA,sedentary behavior,and sleep quality(NCT04499547).Methods:Sixty-four young adults(48 females;age=22.8±3.4 years,mean±SD;body mass index=23.1±2.6 kg/m²)were randomized(1:1)into the intervention group,which received weekly aerobic and muscle-strengthening PA videos,or control group,which received weekly general health education videos,for 12 weeks.Our primary outcome was free-living moderate-to-vigorous PA(MVPA)and our secondary outcomes were sedentary behavior,light PA,and sleep quality(measured using ActiGraph accelerometers)along with muscle-strengthening PA frequency,self-determination theory-related motivation(non-regulation,external regulation,introjected regulation,identified regulation,integrated regulation,and intrinsic regulation),and perceived PA barriers(assessed using validated questionnaires).Repeated measures analysis of variances(ANOVAs)examined between-group differences at an adjusted significance level of 0.004 and effect sizes as partial eta-squared(η;).Results:We observed statistically significant interaction effects for MVPA,sleep efficiency,muscle-strengthening PA frequency,non-regulation,integrated regulation,intrinsic regulation,and perceived PA barriers(F(1,62)=10.75-77.67,p<0.001-0.002,η_p²=0.15-0.56)with all outcomes favoring the intervention group.We observed no statistically significant differences in either group for sedentary behavior,light PA,sleep duration,or external,introjected,and identified regulations after 12 weeks(F(1,62)=1.11-3.64,p=0.06-0.61).Conclusion:With national COVID-19 restrictions still in place and uncertainty regarding post-pandemic PA environments and behaviors,a remote,YouTube-delivered PA intervention may help foster clinically meaningful improvements in young adults’free-living MVPA,musclestrengthening PA frequency,sleep efficiency,PA-related intrinsic motivation,and perceived PA barriers.     

The moderating effect of physical activity on the relationship between bullying and mental health among sexual and gender minority youth

BackgroundSexual and gender minority youth frequently experience bullying, which often contributes to higher depressive symptoms and lower self-esteem. Given that physical activity (PA) can mitigate depressive symptoms and improve self-esteem, we examined the moderating effect of PA on the relationship between bullying and mental health among sexual and gender minority youth.MethodsData from the Lesbian, Gay, Bisexual, Transgender, and Queer National Teen Survey (n = 9890) were analyzed. Hierarchical regression analyses examined the influence of history and frequency of being bullied, PA, and the interaction of these variables on depressive symptoms and self-esteem. Simple slopes analyses were used to probe significant interactions.ResultsResults indicated the importance of accounting for bullying history when examining effects of PA on mental health. PA was negatively related to depression (t = –4.18, p < 0.001) and positively related to self-esteem (t = 12.11, p < 0.001). Bullying frequency was positively related to depression (t = 19.35, p < 0.001) and negatively related to self-esteem (t = –12.46, p < 0.001). There was a significant interaction between bullying frequency and PA for depression (t = 4.45, p < 0.001) and self-esteem (t = –4.69, p < 0.001). Post hoc analyses suggested that the positive effects of PA on mental health may be limited to those not bullied because it had a negligible effect on those who were bullied.ConclusionResults suggest that sexual and gender minority youth exercise interventions aiming to improve mental health should first address bullying history; otherwise, their effectiveness may be limited to those who have been bullied.     

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

BackgroundPhysical 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.MethodsParticipants from the 2013 to 2018 annual 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 PA-insomnia 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.ResultsThere 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.ConclusionThese findings highlight the potential benefit of interventions targeting both PA and insomnia symptoms for promoting mental health.     

The impact of the coronavirus disease 2019 pandemic on physical activity in U.S. children

BackgroundDaily moderate-to-vigorous physical activity (MVPA) is vital to the physical, mental, and social well-being of children. Early restrictions during the coronavirus disease 2019 (COVID-19) pandemic included the closure of schools and physical activity (PA) amenities across the US. This study aimed to examine the impact of the pandemic on the PA and play behavior of U.S. children and to provide evidence-based recommendations to improve their PA.MethodsA cross-sectional, online, parent-reported survey was conducted of children aged 3–18 years between April and June 2020 to assess light PA and MVPA using a modified Godin Leisure-Time Exercise Questionnaire. Additional items included family/child socioeconomic demographics, child adaptability to the pandemic, and community access. The survey was shared through social media and snowball sampling distribution.ResultsAnalysis of 1310 surveys indicated child PA scores declined significantly during the pandemic (from 56.6 to 44.6, max 119, p < 0.001). Specifically, MVPA score decreased (from 46.7 to 34.7, max 98, p < 0.001) while light PA remained the same. Age-based changes were seen in the quantity, variety, and intensity of PA, with the lowest pandemic-related impact seen in preschoolers and the highest in high schoolers (–4.7 vs. –17.2, p < 0.001). Community-based peer PA decreased across all age groups.ConclusionThis study shows decreased PA levels in U.S. children, according to parent reporting, during the COVID-19 pandemic. Recommendations for community leaders, educators, and parents to improve PA in children are provided. With continued spread of COVID-19, these results and recommendations may be imperative to the physical well-being of U.S. children.     

The effects of resistance training on muscular strength and hypertrophy in elderly cancer patients: A systematic review and meta-analysis

Background:One of the most life-threatening comorbidities in elderly cancer patients is cancer cachexia,which is characterized by the ongoing loss of skeletal muscular strength and mass and is also associated with aging.There is a lack of recommendations for optimal resistance training(RT) for those patients.The purpose of this study was to systematically review and quantify the effects of RT on muscular strength and hypertrophy in elderly cancer patients.Methods: Five electronic databases were searched(until January 2020) for studies that met the following criteria:(i) cancer patients aged>60 years;(ii) structured and supervised RT intervention for>6 weeks;and(iii) measured muscular strength and/or hypertrophy.Results:Thirteen studies(717 participants,average age=66 years) met the inclusion criteria.RT significantly increased muscular strength(mean effect size=0.87,95% confidence interval(95%CI):0.43-1.32,p <0.001) and did not significantly induce muscle hypertrophy(mean effect size=0.09,95%CI:-0.14 to 0.31,p=0.45).In subgroup analyses for muscle strength,higher weekly frequency was significantly associated with larger effect size.Egger’ s test showed no significant publication bias for the 2 outcomes.Conclusion:The results suggest that RT improves muscular strength but does not significantly induce muscle hypertrophy in elderly cancer patients.     

Back to school after lockdown: The effect of COVID-19 restrictions on children's device-based physical activity metrics

BackgroundThe coronavirus disease-2019 (COVID-19) pandemic and national lockdowns took away opportunities for children to be physically active. This study aimed to determine the effect of the COVID-19 lockdown on accelerometer-assessed physical activity (PA) in children in Wales.MethodsEight hundred participants (8–18 years old), stratified by sex, age, and socio-economic status, wore Axivity AX3 accelerometers for 7 days in February 2021, during the lockdown, and in May 2021, while in school. Raw accelerometer data were processed in R-package GGIR, and cut-point data, average acceleration (AvAcc), intensity gradient, and the acceleration above which the most active X minutes are accumulated (MX) metrics were extracted. Linear mixed models were used to assess the influence of time-point, sex, age, and socioeconomic status (SES) on PA.ResultsDuring lockdown, moderate-to-vigorous PA was 38.4 ± 24.3 min/day; sedentary time was 849.4 ± 196.6 min/day; mean ± SD. PA levels increased significantly upon return to school (all variables p < 0.001). While there were no sex differences during lockdown (p = 0.233), girls engaged in significantly less moderate-to-vigorous PA than boys once back in school (p < 0.001). Furthermore, boys had more favorable intensity profiles than girls (intensity gradient: p < 0.001), regardless of time-point. PA levels decreased with age at both time-points; upper secondary school girls were the least active group, with an average M30 of 195.2 mg (while in school).ConclusionThe lockdown affected boys more than girls, as reflected by the disappearance of the typical sex difference in PA levels during lockdown, although these were re-established on return to school. Upper secondary school (especially girls) might need specific COVID-recovery intervention.     

Replacement of leisure-time sedentary behavior with various physical activities and the risk of dementia incidence and mortality: A prospective cohort study

BackgroundWhether or not there is targeted pharmacotherapy for dementia, an active and healthy lifestyle that includes physical activity (PA) may be a better option than medication for preventing dementia. We examined the association between leisure-time sedentary behavior (SB) and the risk of dementia incidence and mortality. We further quantified the effect on dementia risk of replacing sedentary time with an equal amount of time spent on different physical activities.MethodsIn the UK Biobank, 484,169 participants (mean age = 56.5 years; 45.2% men) free of dementia were followed from baseline (2006–2010) through July 30, 2021. A standard questionnaire measured individual leisure-time SB (watching TV, computer use, and driving) and PA (walking for pleasure, light and heavy do-it-yourself activity, strenuous sports, and other exercise) frequency and duration in the 4 weeks prior to evaluation. Apolipoprotein E (APOE) genotype data were available for a subset of 397,519 (82.1%) individuals. A Cox proportional hazard model and an isotemporal substitution model were used in this study.ResultsDuring a median 12.4 years of follow-up, 6904 all-cause dementia cases and 2115 deaths from dementia were recorded. In comparison to participants with leisure-time SB <5 h/day, the hazard ratio ((HR), 95% confidence interval (95%CI)) of dementia incidence was 1.07 (1.02–1.13) for 5–8 h/day and 1.25 (1.13–1.38) for >8 h/day, and the HR of dementia mortality was 1.35 (1.12–1.61) for >8 h/day. A 1 standard deviation increment of sedentary time (2.33 h/day) was strongly associated with a higher incidence of dementia and mortality (HR = 1.06, 95%CI: 1.03–1.08 and HR = 1.07, 95%CI: 1.03–1.12, respectively). The association between sedentary time and the risk of developing dementia was more profound in subjects <60 years than in those ≥60 years (HR = 1.26, 95%CI: 1.00–1.58 vs. HR = 1.21, 95%CI: 1.08–1.35 in >8 h/day, p for interaction = 0.013). Replacing 30 min/day of leisure sedentary time with an equal time spent in total PA was associated with a 6% decreased risk and 9% decreased mortality from dementia, with exercise (e.g., swimming, cycling, aerobics, bowling) showing the strongest benefit (HR = 0.82, 95%CI: 0.78–0.86 and HR = 0.79, 95%CI: 0.72–0.86). Compared with APOE ε4 noncarriers, APOE ε4 carriers are more likely to see a decrease in Alzheimer's disease incidence and mortality when PA is substituted for SB.ConclusionLeisure-time SB was positively associated with the risk of dementia incidence and mortality. Replacing sedentary time with equal time spent doing PA may be associated with a significant reduction in dementia incidence and mortality risk.