Teacher and school outcomes of the Physical Education and Physical Literacy (PEPL) approach: a pragmatic cluster randomised controlled trial of a multicomponent intervention to improve physical literacy in primary schools

ABSTRACT

Background: Physical education (PE) can be considered the centrepiece of school physical literacy (PL) programs, but ineffective lessons or an absence of PE across the public primary school system has raised concern. This study aimed to evaluate the implementation, acceptability and impact of teacher delivery of PE as part of a multicomponent Physical Education Physical Literacy (PEPL) approach, designed to improve classroom teachers’ provision of PE and PL opportunities within a cluster of suburban primary schools.

Method: Within a pragmatic randomised cluster-based trial with mixed methods, a PEPL coach was appointed to seven schools for one school year, with another seven schools continuing their usual practice as the control group. The coach’s role was to support and professionally develop classroom teachers to teach PE and to create opportunities that develop PL inside and outside the school environment. Focusing on Grade 5 teachers, the implementation, acceptability and teacher impact were assessed using direct observations of PE teaching style, a daily log kept by the coach and interviews with principals and teachers.

Results: The PEPL coach visited each school on average once a week for the 33 available weeks of the school year. There were several positive effects for teachers and schools. With no classroom teacher initially taking PE or classroom physical activity breaks, all seven teachers regularly introduced a PE lesson and activity breaks into their weekly schedule. PE class instructional time increased (intervention; +4.8 vs. control; ?3.5 min/lesson; β?=?1.69; SE?=?0.76; p?=?.05), with lessons of greater duration (intervention; +8.6 vs. control +1.9 min/lesson; β?=?1.14, SE?=?0.58, p?=?.05) and moderate and vigorous physical activity increased 5.7 min in intervention classes (p?<?.05). The PEPL coach introduced regular physical activities before and after school and linked the schools with a national sports coaching scheme. Interviews indicated that the PEPL approach was both valued and well-accepted by staff, that classroom teacher confidence to teach PE increased and that principals perceived a shift toward a school ‘culture’ of physical activity.

Conclusions: Well-received by classroom teachers and principals, the PEPL approach resulted in classroom teachers introducing both PE and activity breaks into their weekly teaching program and schools were linked to external sport coaching programs. These effects suggest that the PEPL approach enhanced opportunities for the development of physical literacy in this suburban primary school setting.

Trial registration: Australian New Zealand Clinical Trials Registry identifier: ACTRN12615000066583.     

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

BackgroundWhile 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.MethodsThis 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 GT3X 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.ResultsTotal-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.ConclusionAssociations 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 LIPA may provide protection from the deleterious effects of sitting on adiposity markers among adolescents. Experimental evidence is needed to support these conclusions.     

Chronotropic incompetence is more frequent in obese adolescents and relates to systemic inflammation and exercise intolerance

BackgroundAdults with obesity may display disturbed cardiac chronotropic responses during cardiopulmonary exercise testing, which relates to poor cardiometabolic health and an increased risk for adverse cardiovascular events. It is unknown whether cardiac chronotropic incompetence (CI) during maximal exercise is already present in obese adolescents and, if so, how that relates to cardiometabolic health.MethodsSixty-nine obese adolescents (body mass index standard deviation score = 2.23 ± 0.32, age = 14.1 ± 1.2 years; mean ± SD) and 29 lean adolescents (body mass index standard deviation score = –0.16 ± 0.84, age = 14.0 ± 1.5 years) performed a maximal cardiopulmonary exercise testing from which indicators for peak performance were determined. The resting heart rate and peak heart rate were used to calculate the maximal chronotropic response index. Biochemistry (lipid profile, glycemic control, inflammation, and leptin) was studied in fasted blood samples and during an oral glucose tolerance test within obese adolescents. Regression analyses were applied to examine associations between the presence of CI and blood or exercise capacity parameters, respectively, within obese adolescents.ResultsCI was prevalent in 32 out of 69 obese adolescents (46%) and 3 out of 29 lean adolescents (10%). C-reactive protein was significantly higher in obese adolescents with CI compared to obese adolescents without CI (p = 0.012). Furthermore, peak oxygen uptake and peak cycling power output were significantly reduced (p < 0.05) in obese adolescents with CI vs. obese adolescents without CI. The chronotropic index was independently related to blood total cholesterol (standardized coefficient β = –0.332; p = 0.012) and C-reactive protein concentration (standardized coefficient β = –0.269; p = 0.039).ConclusionCI is more common in the current cohort of obese adolescents, and is related to systemic inflammation and exercise intolerance.     

Twenty-four-hour movement guidelines during middle adolescence and their association with glucose outcomes and type 2 diabetes mellitus in adulthood

Purpose:The aim of the present study was to determine the association between adherence to the 24-h movement guidelines during middle adolescence and glucose outcomes(glycated hemoglobin and fasting glucose) and type 2 diabetes mellitus(T2DM) in adulthood,14 and 22 years later.Methods:We analyzed data from apparently healthy adolescents aged 12-18 years who participated in Waves Ⅰ and Ⅱ(1994-1996,n=14,738),Wave Ⅳ(2008-2009,n=8913),and Wave V(2016-2018,n=3457) of the National Longitudinal Study o...     

Validity of long-term and short-term recall of occupational sitting time in Finnish and Chinese office workers

BackgroundAs sedentary behavior is a global health issue, there is a need for methods of self-reported sitting assessment. The accuracy and reliability of these methods should also be tested in various populations and different cultural contexts. This study examined the validity of long-term and short-term recall of occupational sitting time in Finnish and Chinese subgroups.MethodsTwo cohort groups of office-based workers (58.6% female, age range 22–67 years) participated: a Finnish group (FIN, n = 34) and a Chinese group (CHI, n = 36). Long-term (past 3-month sitting) and short-term (daily sitting assessed on 5 consecutive days) single-item measures were used to assess self-reported occupational sitting time. Values from each participant were compared to objectively measured occupational sitting time assessed via thigh-mounted accelerometers, with Spearman's rho (ρ) used to assess validity and the Bland-Altman method used to evaluate agreement. Coefficients of variation depicted day-to-day variability of time spent on sitting at work.ResultsIn the total study sample, the results showed that both long-term and short-term recall correlated with accelerometer-derived sitting time (ρ = 0.532, 95% confidence intervals (CI): 0.336–0.684, p < 0.001; ρ = 0.533, 95%CI: 0.449–0.607, p < 0.001, respectively). Compared to objectively measured sitting time, self-reported occupational sitting time was 2.4% (95%CI: −0.5% to 5.3%, p = 0.091) and 2.2% (95%CI: 0.7%–3.6%, p = 0.005) greater for long-term and short-term recall, respectively. The agreement level was within the range −21.2% to 25.9% for long-term recall, and −24.2% to 28.5% for short-term recall. During a 5-day work week, day-to-day variation of sitting time was 9.4% ± 11.4% according to short-term recall and 10.4% ± 8.4% according to accelerometry-derived occupational sitting time.ConclusionOverall, both long-term and short-term self-reported instruments provide acceptable measures of occupational sitting time in an office-based workplace, but their utility at the individual level is limited due to large variability.     

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.     

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.     

Transferring primary generalists’ positive classroom pedagogy to the physical education setting: a collaborative PE-CPD process

Background: The primary school age group (aged 5–11 years) is acknowledged as a critical period in the development of physical activity patterns and healthy lifestyle behaviours. Furthermore, high quality physical education (PE) is crucial for the development of lifelong physical activity behaviours and is highly dependent on the interaction between the teacher and the pupil. Despite this, there is a lack of training and confidence of many primary generalist teachers to teach PE in the UK. It is argued that effective continuing professional development (CPD) to address this issue should be supportive, job embedded, instructionally focused, collaborative and ongoing.

Purpose: This study was funded by a national government funded organisation and led by a university in collaboration with a secondary PE specialist and two primary teachers. The purpose was to develop a replicable PE-CPD process to improve primary generalist teachers’ PE pedagogy by transferring their positive pedagogy from the classroom to the PE setting.

Participants: The participants were two Year 3 (age 7–8 years) primary classroom teachers from the same school and one secondary PE specialist teacher who acted as a mentor.

Research approach: A collaborative professional learning (CPL) approach was utilised to develop the PE-CPD intervention process. CPL involves teachers and other members of a profession working together to improve their own and others’ learning on pedagogic issues. A six-week needs assessment phase was completed through classroom and PE lesson observations to identify key areas for development in the PE-CPD process over the duration of a 23 week intervention.

Data collection and analysis: Reflective logs, structured lesson observations and teacher interviews were used to collect the data during the PE-CPD intervention. Inductive and deductive qualitative thematic analysis was used to analyse and interpret the data.

Findings: A number of key themes were generated during the data analysis including the transfer of positive pedagogy from the classroom to the PE setting and the implementation of effective pedagogic principles including the setting of clear learning outcomes, differentiation and inclusion to enhance the PE pedagogy. A key element to the success of the intervention was the trusting relationships built by the secondary PE specialist with the primary teachers. Further, the results also revealed the importance of CPL in ensuring rigorous, evidence-based PE-CPD and providing the time and support required for fundamental sustainable changes in practice, which can endure beyond the life of the research project.

Conclusion: The major contribution of this paper is in demonstrating the potential of CPL between national organisations, universities, secondary and primary schools to improve the PE pedagogy of primary generalist teachers. Future research should build upon the findings in this study and replicate this PE-CPD approach with other classes and schools.     

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.     

Postural control quantification in minimally and moderately impaired persons with multiple sclerosis: The reliability of a posturographic test and its relationships with functional ability

BackgroundPostural control has been associated with the functional impairment in persons with multiple sclerosis (pwMS). However, there is a need for reliable methods to assess postural control in early stages of the disease, when subtle changes can be difficult to detect. The aims of this study were to assess the absolute and relative reliability of a standing and a sitting posturographic protocol in minimally (Expanded Disability Status Scale ≤ 2) and moderately (2.5 ≤ Expanded Disability Status Scale ≤ 4) impaired pwMS, and to analyze relationships among postural control and functional mobility and gait performance.MethodsTo assess postural control in an upright stance, 14 minimally and 16 moderately impaired pwMS performed six 70 s trials in tandem stance, 3 with their weaker leg behind (TS_WL) and 3 with their stronger leg behind (TS_SL). Additionally, participants completed five 70 s trials using an unstable sitting protocol (US) to assess trunk stability. The mean radial errors of TS_WL, TS_SL, and US trials were calculated as postural control indexes. Furthermore, participants performed the Timed Up and Go test (TUG) and the Timed 25-foot Walk test (T25FW) to measure their functional mobility and gait speed, respectively. Reliability was evaluated using the intraclass correlation coefficient (ICC_3,1) and the standard error of measurement (SEM). Analyses of variances were carried out to assess between-group differences. Hedges’ g index (d_g) was used to estimate the effect size of differences. Pearson correlation analyses (r) were performed to examine the relationships among the postural control and the functional tests.ResultsPosturographic tests showed a high reliability in both minimally (0.87 ≤ ICC ≤ 0.92; 9.32% ≤ SEM ≤ 11.76%) and moderately (0.80 ≤ ICC ≤ 0.92; 10.33% ≤ SEM ≤ 15.33%) impaired pwMS. Similarly, T25FW and TUG displayed a high consistency in minimally (0.89 ≤ ICC ≤ 0.94; 3.43% ≤ SEM ≤ 5.17%) and moderately (0.85 ≤ ICC ≤ 0.93; 5.57% ≤ SEM ≤ 6.56%) impaired individuals. Minimally impaired pwMS showed a better performance on the TUG, T25FW, and TS_WL than moderately impaired individuals (p < 0.05; d_g ≥ 0.8). The TS_WL, TS_SL, and US variables correlated with TUG scores (0.419 ≤ r ≤ 0.604; p < 0.05), but TS_WL also correlated with T25FW scores (r = 0.53; p < 0.01). Furthermore, US scores correlated with both tandem stance parameters (TS_WL: r = 0.54, p < 0.01; TS_SL: r = 0.43, p < 0.05).ConclusionTandem and sitting posturographic tests provide reliable measures of postural control in pwMS, even in individuals with a homogeneous disease profile. Gait speed, functional mobility, and weaker leg status seem decisive in assessing the degree of physical activity limitation in pwMS. Finally, although trunk stability does not seem to be so affected by the course of the disease, it remains relevant for postural control and functional capacity.     

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.     

One hundred marathons in 100 days: Unique biomechanical signature and the evolution of force characteristics and bone density

BackgroundAn extraordinary long-term running performance may benefit from low dynamic loads and a high load-bearing tolerance. An extraordinary runner (age = 55 years, height = 1.81 m, mass = 92 kg) scheduled a marathon a day for 100 consecutive days. His running biomechanics and bone density were investigated to better understand successful long-term running in the master athlete.MethodsOverground running gait analysis and bone densitometry were conducted before the marathon-a-day challenge and near its completion. The case's running biomechanics were compared pre-challenge to 31 runners who were matched by a similar foot strike pattern.ResultsThe case's peak vertical loading rate (Δx? = –61.9 body weight (BW)/s or –57%), peak vertical ground reaction force (Δx? = –0.38 BW or –15%), and peak braking force (Δx? = –0.118 BW or –31%) were remarkably lower (p < 0.05) than the control group at ～3.3 m/s. The relatively low loading-related magnitudes were attributed to a remarkably high duty factor (0.41) at the evaluated speed. The foot strike angle of the marathoner (29.5°) was greater than that of the control group, affecting the peak vertical loading rate. Muscle powers in the lower extremity were also remarkably low in the case vs. controls: peak power of knee absorption (Δx? = –9.16 watt/kg or –48%) and ankle generation (Δx? = –3.17 watt/kg or –30%). The bone mineral density increased to 1.245 g/cm² (+2.98%) near completion of the challenge, whereas the force characteristics showed no statistically significant change.ConclusionThe remarkable pattern of the high-mileage runner may be useful in developing or evaluating load-shifting strategies in distance running.     

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).     

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.     

Does exercise have a protective effect on cognitive function under hypoxia? A systematic review with meta-analysis

ObjectiveThis study aimed to examine (1) the independent effects of hypoxia on cognitive function and (2) the effects of exercise on cognition while under hypoxia.MethodsDesign: Systematic review with meta-analysis. Data sources: PubMed, Scopus, Web of Science, PsychInfo, and SPORTDiscus were searched. Eligibility criteria for selecting studies: randomized controlled trials and nonrandomized controlled studies that investigated the effects of chronic or acute exercise on cognition under hypoxia were considered (Aim 2), as were studies investigating the effects of hypoxia on cognition (Aim 1).ResultsIn total, 18 studies met our inclusionary criteria for the systematic review, and 12 studies were meta-analyzed. Exposure to hypoxia impaired attentional ability (standardized mean difference (SMD) = –0.4), executive function (SMD = –0.18), and memory function (SMD = –0.26), but not information processing (SMD = 0.27). Aggregated results indicated that performing exercise under a hypoxia setting had a significant effect on cognitive improvement (SMD = 0.3, 95% confidence interval: 0.14 – 0.45, I² = 54%, p < 0.001). Various characteristics (e.g., age, cognitive task type, exercise type, exercise intensity, training type, and hypoxia level) moderated the effects of hypoxia and exercise on cognitive function.ConclusionExercise during exposure to hypoxia improves cognitive function. This association appears to be moderated by individual and exercise/hypoxia-related characteristics.     

Stair climbing,genetic predisposition,and the risk of incident type 2 diabetes: A large population-based prospective cohort study

Background:Cross-sectional evidence and small-scale trials suggest positive effects of stair climbing on cardiometabolic disease and glucose regulation.However,few studies have examined the long-term association between stair climbing and the incidence of type 2 diabetes(T2D).We aimed to prospectively evaluate the association of stair climbing with T2D and assess modifications by genetic predisposition to T2D.Methods:We included 451,699 adults(mean age=56.3±8.1 years,mean±SD;55.2% females) witho...     

No independent associations between physical activity and clinical outcomes among hospitalized patients with moderate to severe COVID-19

BackgroundRegular physical activity (PA) has been postulated to improve, or at least maintain, immunity across the life span. However, the link between physical (in)activity and coronavirus disease 2019 (COVID-19) remains to be established. This small-scale prospective cohort study is nested within a randomized controlled trial aimed to investigate the possible associations between PA levels and clinical outcomes among hospitalized patients with moderate to severe COVID-19.MethodsHospitalized patients with COVID-19 (mean age: 54.9 years) were recruited from the Clinical Hospital of the School of Medicine of the University of Sao Paulo (a quaternary referral teaching hospital) and from Ibirapuera Field Hospital, both located in Sao Paulo, Brazil. PA level was assessed using the Baecke Questionnaire of Habitual Physical Activity. The primary outcome was hospital length of stay. The secondary outcomes were mortality, admission to the intensive care unit (ICU), and mechanical ventilation requirement.ResultsThe median hospital length of stay was 7.0 ± 4.0 days, median ± IQR; 3.3% of patients died, 13.8% were admitted to the ICU, and 8.6% required mechanical ventilation. Adjusted linear regression models showed that PA indices were not associated with hospital length of stay (work index: β = –0.57 (95% confidence interval (95%CI): –1.80 to 0.65), p = 0.355; sport index: β = 0.43 (95%CI: –0.94 to 1.80), p = 0.536; leisure-time index: β = 1.18 (95%CI: –0.22 to 2.59), p = 0.099; and total activity index: β = 0.20 (95%CI: –0.48 to 0.87), p = 0.563). None of the PA indices were associated with mortality, admission to the ICU, or mechanical ventilation requirement (all p > 0.050).ConclusionAmong hospitalized patients with COVID-19, PA did not independently associate with hospital length of stay or any other clinically relevant outcomes. These findings should be interpreted as meaning that, among already hospitalized patients with more severe forms of COVID-19, being active is a potential protective factor likely outweighed by a cluster of comorbidities (e.g., type 2 diabetes, hypertension, weight excess) and older age, suggesting that the benefit of PA against the worsening of COVID-19 may vary across stages of the disease.     

Number of parous events affects the association between physical exercise and glycemic control among women with gestational diabetes mellitus: A prospective cohort study

BackgroundMultiparous women are at a higher risk of gestational diabetes mellitus (GDM) than primiparas. Physical activity during pregnancy has been shown to be beneficial for GDM, but there is little evidence on the association between physical activity and glycemic control among women with GDM, whether primiparas or multiparas. Thus, the objective of the present study was to examine the association between physical activity and glycemic control in women with GDM and to determine what, if any, effects result from number of parous events.MethodsA prospective cohort of 1162 women with GDM was recruited, with 604 multiparas (51.98%). The general linear model was used to calculate the risk difference and its 95% confidence interval (95%CI) to quantify the impact of parous events on glycemic control in pregnancy as well as the association between physical activity time and glycemic control.ResultsAmong 1162 women with GDM, the median daily activity time was 65 min (interquartile range (IQR): 45–90 min), and the abnormal plasma glucose (PG) percentage, calculated as number of abnormal PG tests divided by the total number of PG tests, was 40.00% (IQR: 22.22%–66.67%). The percentage of abnormal PG was stabilized and statistically lower with daily physical activity time exceeding 60 min among primiparas (IQR: 30.89%–44.43%) and exceeding 90 min among multiparas (ranged from 27.76% to 38.82%). After adjusting for potential confounders, primiparas tended to have a lower percentage of abnormal PG than do multiparas (rate difference = –0.39, 95%CI: –3.61 to 2.84). The same amount of physical activity time was significantly less effective for multiparas than for primiparas (trend p-value < 0.01).ConclusionIn women with GDM, being multiparous is associated with less effective glycemic control through physical activity, such that multiparas need more physical activity to achieve glycemic control at a similar level to primiparas.