Between-school variation in physical activity,aerobic fitness,and organized sports participation: A multi-level analysis

Abstract

A large proportion of a child's day is spent at school interacting with certain physical surroundings, teachers, and school friends. Thus, schools could have a marked impact on establishing physical activity habits. The aim of the present study was to assess between-school variation in physical activity, aerobic fitness, and organized sports participation. Altogether, we tested 1766 nine- and fifteen-year-old children attending 242 school classes at 35 different schools in Denmark in 1997–2003. The intra-class correlation coefficient (ICC) for objectively assessed physical activity ranged between 0.06 and 0.18 depending on the dimension of physical activity and the time considered (i.e. school time vs. leisure time). For aerobic fitness, an ICC of 0.10 was observed, whereas that for organized sports participation ranged between 0.01 and 0.10 depending on the age group. Studying between-school variation in physical activity provides information about the extent to which children adjust their physical activity habits according to the social and environmental circumstances that they share, and helps to plan future school-based physical activity studies, especially in terms of sample size and power calculation.     

记忆编码后短时有氧运动对长时记忆固化的影响

探讨了记忆编码后短时有氧运动对长时记忆的影响,以及运动强度这一因素在短时有氧运动与长时记忆关系中的作用。实验选取48名在校大学生（男女各半）,分为控制组、低强度运动组和高强度运动组,运动组进行30 min不同强度的有氧运动,控制组则不进行运动。通过测试一周后对之前学习的中性词汇的再认成绩来评价长时记忆固化水平。结果表明,不同有氧运动强度对长时记忆固化的影响存在差异：高强度短时有氧运动能够显著提升长时记忆固化水平（P＜0.05＝,低强度短时有氧运动对长时记忆固化水平则不产生显著影响（P ＞0.05）。不同强度有氧运动对长时记忆的影响不随性别变化而改变。     

Effects of aerobic and cognitively-engaging physical activity on academic skills: A cluster randomized controlled trial

ABSTRACT

This cluster randomized controlled trial (trial-number #) compares effects of two school-based physical activity interventions (aerobic vs. cognitively-engaging) on reading, mathematics, and spelling achievement; and whether effects are influenced by volume of moderate-to-vigorous physical activity and baseline achievement. Twenty-two primary schools participated, where a third and fourth grade class were randomly assigned to the intervention or control group. Intervention groups were randomly assigned to a 14-week aerobic or cognitively-engaging intervention, receiving four physical education lessons a week. Control groups followed their regular physical education program. Academic achievement of 891 children (mean age 9.17 years, 49.4% boys) was assessed with standardized tests before and after the interventions. Post-Test academic achievement did not significantly differ between intervention groups and control group. A higher volume of moderate-to-vigorous physical activity resulted in better post-test mathematics achievement in both intervention groups, and post-test spelling achievement in the cognitively engaging intervention group. Compared to the control group, lower achievers in reading performed better in reading after the cognitively-engaging intervention. A combination of moderate-to-vigorous physical activity and cognitively-engaging exercises seems to have the most beneficial effects. Future intervention studies should take into account quantitative and qualitative aspects of physical activity, and children’s baseline academic achievement.     

有氧锻炼负荷强度对儿童心理健康的影响

选取年龄在10．15岁儿童，共计320人为研究对象。实验组儿童参与不同强度的有氧锻炼，对照组儿童在实验中以常规教学或自习课为主。实验前、后分别用MHT测量儿童的心理健康，并用EFI测量儿童的锻炼感觉和运动愉快感。结果表明：(1)实验组儿童实验前后的心理健康状况存在极显性差异(除低年级儿童大强度组外)；对照组儿童则没有显性变化。(2)低年级儿童参与中、小强度的有氧锻炼与参与大强度的有氧锻炼存在锻炼心理效应和运动愉快感的显性差异；高年级儿童参与大、中强度的有氧锻炼与小强度的有氧锻炼存在锻炼心理效应和运动愉快感的显性差异。(3)低年级儿童参与不同强度的有氧锻炼没有性别差异；高年级儿童参与不同强度的有氧锻炼存在锻炼心理效应的显性的性别差异。根据实验结果得出：参与适宜强度的有氧锻炼有助于增强儿童的心理健康。     

In-school and out-of-school physical activity in primary and secondary school children

The aim of this study was to compare in-school and out-of-school physical activity within a representative sample. Socio-demographic, physical activity, and anthropometric data were collected from a random sample of children (250 boys, 253 girls) aged 3-16 years attending nine primary and two secondary schools. Actigraph GT1M accelerometers, worn for seven days, were used to estimate physical activity levels for in-school (typically 09.00-15.00 h), out-of-school (weekday), and weekend periods. Physical activity as accelerometer counts per minute were lower in school versus out of school overall (in school: 437.2 +/- 172.9; out of school: 575.5 +/- 202.8; P < 0.001), especially in secondary school pupils (secondary: 321.6 +/- 127.5; primary: 579.2 +/- 216.3; P < 0.001). Minutes of moderate-to-vigorous physical activity accumulated in school accounted for 29.4 +/- 9.8% of total weekly moderate-to-vigorous physical activity overall but varied by sector (preschool: 37.4 +/- 6.2%; primary: 33.6 +/- 8.1%; secondary: 23.0 +/- 9.3%; F = 114.3, P < 0.001). Approximately half of the children with the lowest in-school activity compensated out of school during the week (47.4%) and about one-third at the weekend (30.0%). Overall, physical activity during the school day appears to be lower than that out of school, especially in secondary school children, who accumulate a lower proportion of their total weekly moderate-to-vigorous physical activity at school than younger children. As low in-school activity was compensated for beyond the school setting by less than half of children, promoting physical activity within the school day is important, especially in secondary schools.     

A Comparison of Self-Report Scales and Accelerometer-Determined Moderate to Vigorous Physical Activity Scores of Finnish School Students

The current article provides an important insight into measurement differences between two commonly used self-reports and accelerometer-determined moderate to vigorous physical activity (MVPA) scores within matched samples across 1 school year. Participants were 998 fifth- through eighth-grade students who completed self-reports and 76 fifth- and sixth-grade children with accelerometers. The Health Behavior in School-aged Children (HBSC) Research Protocol showed the higher frequency of days exceeding 60 minutes of MVPA than the International Physical Activity Questionnaire Short Form (IPAQ-SF). Larger proportions of children achieved the MVPA guidelines based on HBSC results (girls 16%, boys 29%), than IPAQ-SF (girls 5%, boys 11%), or accelerometers data (girls 0%, boys 0%). MVPA remained stable over 12 months on the basis of both self-report and accelerometer results. Both self-report scales presented should be used with discretion in population studies, whereas accelerometer-determined data can be more authentic when personal guidance is required.     

Steps counts among middle school students vary with aerobic fitness level

The purpose of this study was to examine if steps/day taken by middle school students varied based on aerobic fitness classification. Middle school students (N = 223; 112 girls, 111 boys) were assigned to three aerobic fitness categories (HIGH, MOD, LOW) based on results of the FlTNESSGRAM PACER test. Four weekdays of pedometer monitoring determined activity levels (steps/day). Boys accumulated significantly more steps/day than girls, 11,589 +/- 3,270 and 10,232 +/- 2,517 steps/day, respectively; F(1,219) = 16.0, p < .001, eta2 = .055. There were no differences in steps/day between grades. HIGH fit participants accumulated significantly more steps/day, F(2, 217) = 12.2, p < .101, eta2 = .101, than moderately fit and low fit participants (approximately 1,491 and ; 2,867 steps/day, respectively). Middle school students who participated in sports in addition to physical education (PE) accumulated significantly more steps/day (approximately 980 steps/day) than those participating in PE only, F(1, 219) = 10.0, p < .01, eta2 = .044. Although the relationship between physical activity and aerobic fitness was moderate (0.35; p < .01), these data demonstrated significant differences in accumulated steps/day among youth of varying aerobic fitness levels. Whether improved fitness levels were the result of additional activity or the cause of it remains to be determined. Regardless, the fittest middle school students were also the most active and accumulated a significant amount of steps/day through organized extracurricular physical activities.     

Effects of high-intensity intermittent running exercise in overweight children

Abstract

This study examined the effects of a 6-week intermittent exercise training, at different intensities, on body composition, functional walking and aerobic endurance in overweight children. Forty-eight overweight children (age: 10.4 ± 0.9 years) were randomly assigned to either intervention or control group. Lower and higher intensity intermittent exercise groups (LIIE and HIIE) performed intermittent running three times a week. LIIE performed more intervals at a lower intensity [16 intervals at 100% of individual maximal aerobic speed (MAS), 8 minutes in total], and HIIE performed fewer intervals at a higher intensity (12 intervals at 120% of MAS, 6 minutes in total). Each interval consisted of a 15-second run at the required speed, followed by a 15-second passive recovery. After 6 weeks, HIIE had a significantly (p < 0.05) higher percentage reduction in sum of skinfolds (i.e. calf and triceps), and significantly (p < 0.05) fewer steps during the functional obstacle performance, as compared with LIIE and control group. Significant improvement (p < 0.05) was found in intermittent aerobic endurance for HIIE as compared to the control group. Higher intensity intermittent training is an effective and time-efficient intervention for improving body composition, functional walking and aerobic endurance in overweight children.     

Multivariate Relationships of Specific Impression Cues with Teacher Expectations and Dyadic Interactions in Elementary Physical Education Classes

Abstract

The purpose of this study was to determine the multivariate relationships of the impression cues of attractiveness and effort with teacher expectations and dyadic interactions in two elementary age groups of children. Three elementary physical education teachers and 128 children (K-3) served as subjects. The children were classified into two groups, one consisting of kindergarten and first grade children and the other second and third grade children. Physical attractiveness was determined from ratings of black and white photographs of each student. Student effort was determined by the ratings of the teachers according to the amount of expressed effort demonstrated by each student during physical activity instruction. Teachers were also asked to rate their students according to four expectancy variables. A dyadic version of Cheffers' Adaptation to Flanders' Interaction Analysis System was the observational tool used to describe teacher-student behaviors. For the older group only, teachers' expectations for the students' social relations, cooperative behavior and ability to reason significantly related to both impression cues. For the younger group, teachers' expectations for social relations and cooperative behavior were significantly related to teacher praise, direction-giving, criticism, and predictable student responses. For the older group, however, the teachers' expectation for cooperative behavior was significantly related to eight behavioral variables, especially to information giving and student-initiated responses.     

Comparative evaluation of heart rate-based monitors: Apple Watch vs Fitbit Charge HR

The purpose of this investigation was to examine the validity of energy expenditure (EE), steps, and heart rate measured with the Apple Watch 1 and Fitbit Charge HR. Thirty-nine healthy adults wore the two monitors while completing a semi-structured activity protocol consisting of 20 minutes of sedentary activity, 25 minutes of aerobic exercise, and 25 minutes of light intensity physical activity. Criterion measures were obtained from an Oxycon Mobile for EE, a pedometer for steps, and a Polar heart rate strap worn on the chest for heart rate. For estimating whole-trial EE, the mean absolute percent error (MAPE) from Fitbit Charge HR (32.9%) was more than twice that of Apple Watch 1 (15.2%). This trend was consistent for the individual conditions. Both monitors accurately assessed steps during aerobic activity (MAPE_Apple: 6.2%; MAPE_Fitbit: 9.4%) but overestimated steps in light physical activity. For heart rate, Fitbit Charge HR produced its smallest MAPE in sedentary behaviors (7.2%), followed by aerobic exercise (8.4%), and light activity (10.1%). The Apple Watch 1 had stronger validity than the Fitbit Charge HR for assessing overall EE and steps during aerobic exercise. The Fitbit Charge HR provided heart rate estimates that were statistically equivalent to Polar monitor.     

有氧耐力训练大鼠定量运动后红细胞的氧化应激

为了解耐力训练大鼠进行一次定量运动后红细胞的运动氧化应激是否降低以及是否减轻了自由基对其的影响。将60只SD大鼠随机分为不训练组(C)、每次训练20 min组(T1)和每次训练40 min组(T2),训练组在跑台上以28 m/min的速度训练6周。取样前各组又随机分为安静组和定量运动组,测试大鼠红细胞中GPX、SOD及Na -K -ATP酶活性和MDA含量。结果发现定量运动后,未训练大鼠SOD、GPX活性及MDA含量升高,Na -K -ATP酶活性下降;20 min训练大鼠SOD及Na -K -ATP酶活性下降,MDA含量和GPX活性升高且变化程度较未训练大鼠小;40 min训练大鼠各指标变化不大。结果提示有氧耐力运动训练能降低定量运动后红细胞的氧化应激,减轻自由基对红细胞的损伤。     

Potential moderators of day-to-day variability in children’s physical activity patterns

Little is known about whether physical activity compensation occurs and, if so, what are potential moderators of such responses. This study examined whether children’s physical activity, sedentary time and energy expenditure on one day was associated with these behaviours the following day, and what factors may moderate observed associations. One hundred and twenty-seven children (8–11 years) wore an ActiGraph accelerometer for eight days. Time spent in sedentary time and physical activity was obtained. Daily energy expenditure was also assessed using a SenseWear Armband (n=98). Moderators examined were sex, age, BMI, fitness, and fundamental movement skills (FMS). Multilevel analyses were conducted using generalized mixed models. On any given day, every additional 10 minutes spent in moderate-to-vigorous physical activity (MVPA) was associated with 9.3 minutes less MVPA the following day. Every additional 10kcal expended on one day was associated with 2.9 fewer kcal expended the following day. Additional time spent sedentary on any given day was associated with less light physical activity the following day in children with lower FMS. The results are largely consistent with the compensation hypothesis, with children appearing to compensate their activity between days. Strategies to minimise potential compensatory changes may be needed for children overall rather than for specific population sub-groups.     

Aerobic training alone or combined with strength training affects fitness in elderly: Randomized trial

Abstract

Purpose: To investigate if combined strength and aerobic training can enhance aerobic capacity in the elderly to a similar extent as aerobic training alone when training duration is matched. Methods: Elderly men and women (age 63.2?±?4.7) were randomized into two intervention groups: an aerobic group (AG, n?=?17) and a combined group (CG, n?=?16). Subjects trained 40?minutes three times a week for 12 weeks. Both groups trained 20 minutes at 65% of heart rate reserve on ergometer cycles followed by another 20 minutes on the ergometer cycles for AG and 20-minute strength training for the lower body for CG. The primary outcome was VO₂max. Secondary outcomes were maximal voluntary contraction (MVC) in isometric knee extension, 1 repetition maximum in three leg exercises, body fat, waist-to-hip ratio, blood pressure and score on the Health Survey Short Form 36 (SF-36). Results: Both groups improved VO₂max (p?<?.01) and MVC (p?<?.001). VO₂max increased 17% confidence interval (CI) [7.4–26] in CG and 26% CI [14.1–38.2] in AG, with no significant difference between groups. MVC increased 22% CI [16.3–27.7] in CG and 9% CI [4.6–13.5] in AG with CG improving MVC more than AG (p?<?.01). CG's score on the general health dimension on the SF-36 health survey improved more than AG's score. Conclusion: Elderly can substitute a part of their aerobic training with strength training and still improve VO₂max to a clinically significant degree when strength training is performed with large muscle groups subsequently to the aerobic training. Combined training additionally improves strength and self-assessed general health more than aerobic training alone.     

Children's Frequency of Participation in Moderate to Vigorous Physical Activities

Abstract

Third and fourth grade boys (n = 422) and girls (n = 390) in four Texas elementary schools reported their participation in moderate to vigorous physical activities (MVPAs) over a 3-day period. Students were surveyed during class on successive days. On a subsample (n = 44), the agreement between reported and observed physical activities during physical education or recess was 86.3%. Running, walking fast, games and sports, and bicycling accounted for 70% of Total MVPAs. Of Total MVPAs reported, 47.0% for boys and 44.6% for girls were 10 min or longer in duration (LMVPA). The average number of LMVPAs per day was 1.7 for both boys and girls. Students reported significantly more occurrences of LMVPAs out of school than during school. Significant interaction between grade and gender indicated that third grade boys reported more Total MVPAs and LMVPAs than third grade girls, but fourth grade boys reported fewer Total MVPAs and LMVPAs than fourth grade girls. During the 3-day reporting period, 12.3% of boys and 13.3% of girls reported no LMVPAs, and 35.6% of boys and girls reported fewer than one LMVPAs per day. While the majority of children reported obtaining at least some activity daily, a substantial proportion of children in this sample reported fewer than one LMVPA daily, indicating that many children may not be obtaining adequate amounts of physical activity.     

有氧运动对大鼠动脉粥样硬化发生发展过程中血浆及心肌血管紧张素II的影响

目的:通过研究不同负荷有氧运动对大鼠动脉粥样硬化发生发展过程中血浆及心肌AngII含量的影响,为动脉粥样硬化运动处方的制定提供一定的理论参考。方法:雄性Wistar大鼠40只,随机分为正常对照组(NC);动脉粥样硬化组(AS);动脉粥样硬化 60min有氧运动组(ASAT1);动脉粥样硬化 120min有氧运动组(ASAT2)。放免法测定血浆及心肌组织AngII。结果:AS组与NC组相比,血浆AngII显著升高(P<0.05);心肌AngII显著升高(P<0.05)。ASAT1、ASAT2两组与AS组相比,血浆AngII显著下降(P<0.05);ASAT1组心肌AngII显著低于AS组(P<0.05)。ASAT2与ASAT1相比心肌AngII显著升高。结论:60min有氧训练可以使大鼠动脉粥样硬化发生发展过程中血浆和心肌组织AngII降低,延缓动脉粥样硬化的进程;120min有氧训练与60min有氧训练相比,使该过程中大鼠血浆和心肌AngII升高。从一定程度上说明较长时间的有氧运动并不能进一步改善动脉粥样硬化。     

Validation of a short physical activity recall questionnaire completed by Spanish adolescents

Abstract

Self-report recall questionnaires are commonly used to measure physical activity in children and adolescents. However, they have been shown to have low to moderate validity, mainly due to inaccuracies in recall activity. The purpose of the present study was to determine the reliability and validity of an adapted version of the Assessment of Physical Activity Levels Questionnaire (APALQ) among a sample of Spanish adolescents. Test–retest reliability of the APALQ was assessed using a sample of 150 adolescents (72 males, 78 females), aged 13.6±1.1 years, who answered the APALQ twice within 7 days. Criterion validity was assessed using a sample of 77 adolescents (50 males, 27 females), aged 13.6±1.1 years, by comparing the APALQ against the Computer Science and Application (CSA) monitor. All participants were volunteers recruited from local schools in the Aragon region of Spain. Test–retest reliability for all items was high with intra-class coefficients of 0.77 for boys and 0.74 for girls. The APALQ demonstrated modest criterion validity with Pearson correlation coefficients (r) ranging from 0.53 between Physical Activity Index (PAI) and CSA minutes of moderate and vigorous physical activity, and 0.47 between PAI and CSA steps per day. When the data were analysed by gender, girls had higher correlations than boys (P < 0.01). The Spanish APALQ seems to be a valid and reliable short self-report physical activity questionnaire.     

In-school and out-of-school physical activity in primary and secondary school children

Abstract

The aim of this study was to compare in-school and out-of-school physical activity within a representative sample. Socio-demographic, physical activity, and anthropometric data were collected from a random sample of children (250 boys, 253 girls) aged 3–16 years attending nine primary and two secondary schools. Actigraph GT1M accelerometers, worn for seven days, were used to estimate physical activity levels for in-school (typically 09.00–15.00 h), out-of-school (weekday), and weekend periods. Physical activity as accelerometer counts per minute were lower in school versus out of school overall (in school: 437.2 ± 172.9; out of school: 575.5 ± 202.8; P < 0.001), especially in secondary school pupils (secondary: 321.6 ± 127.5; primary: 579.2 ± 216.3; P < 0.001). Minutes of moderate-to-vigorous physical activity accumulated in school accounted for 29.4 ± 9.8% of total weekly moderate-to-vigorous physical activity overall but varied by sector (preschool: 37.4 ± 6.2%; primary: 33.6 ± 8.1%; secondary: 23.0 ± 9.3%; F = 114.3, P < 0.001). Approximately half of the children with the lowest in-school activity compensated out of school during the week (47.4%) and about one-third at the weekend (30.0%). Overall, physical activity during the school day appears to be lower than that out of school, especially in secondary school children, who accumulate a lower proportion of their total weekly moderate-to-vigorous physical activity at school than younger children. As low in-school activity was compensated for beyond the school setting by less than half of children, promoting physical activity within the school day is important, especially in secondary schools.     

Adolescent physical fitness and activity as predictors of adulthood activity

A 25-year population-based study was conducted to determine how physical fitness and participation in leisure-time physical activity in adolescence (age 12-18 years) predict leisure-time physical activity in adulthood (age 37-43 years). In 1976, five field tests were conducted to measure muscular fitness, agility and aerobic capacity, and self-report weekly frequencies of activity were obtained by questionnaire. A modified questionnaire was repeated in 2001, when participants were age 37-43 years (N = 1525). On the basis of the questionnaire, a physical activity index was calculated both in 1976 and 2001. The odds ratios (OR) for being inactive in adulthood among those who were physically very active in adolescence compared with those who were inactive in adolescence was 0.13 for males (95%CI: 0.06-0.31) and 0.28 for females (95%CI: 0.13-0.59). The odds ratio for adult inactivity among males in the highest versus lowest fitness group in adolescence was 0.24 (95%CI: 0.07-0.81). Activity in adolescence predicted activity in adulthood in both males and females. The risk for adult inactivity was significantly lower for those who were physically active in adolescence. In addition, high fitness predicted adult activity among males but not among females.     

Children's frequency of participation in moderate to vigorous physical activities

Third and fourth grade boys (n = 422) and girls (n = 390) in four Texas elementary schools reported their participation in moderate to vigorous physical activities (MVPAs) over a 3-day period. Students were surveyed during class on successive days. On a subsample (n = 44), the agreement between reported and observed physical activities during physical education or recess was 86.3%. Running, walking fast, games and sports, and bicycling accounted for 70% of Total MVPAs. Of Total MVPAs reported, 47.0% for boys and 44.6% for girls were 10 min or longer in duration (LMVPA). The average number of LMVPAs per day was 1.7 for both boys and girls. Students reported significantly more occurrences of LMVPAs out of school than during school. Significant interaction between grade and gender indicated that third grade boys reported more Total MVPAs and LMVPAs than third grade girls, but fourth grade boys reported fewer Total MVPAs and LMVPAs than fourth grade girls reported fewer Total MVPAs and LMVPAs than fourth grade girls. During the 3-day reporting period, 12.3% of boys and 13.3% of girls reported no LMVPAs, and 35.6% of boys and girls reported fewer than one LMVPAs per day. While the majority of children reported obtaining at least some activity daily, a substantial proportion of children in this sample reported fewer than one LMVPA daily, indicating that many children may not be obtaining adequate amounts of physical activity.