首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 32 毫秒
1.
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.  相似文献   

2.
Cardiorespiratory fitness (CRF) is associated with health benefits in children, improving cardiac morphology, cardiovascular disease risk factors, and biological outcomes. This study aimed to examine the substitution effects of displaying a fixed duration of sedentary time with a fixed duration of physical activity (PA) at different intensities on children’s CRF. A total of 315 children (136 boys) were assessed (age: 10.6 ± 0.6 years old). Outcomes at baseline and follow-up (16-months) were CRF determined using a maximal cycle test and sedentary time and PA measured with accelerometers. Data were analysed by isotemporal substitution analyses estimating the effect of reallocating 30 min/day of sedentary time by light (LPA), moderate (MPA) and vigorous physical activity (VPA) on CRF. VPA was positively and significantly associated with CRF cross-sectional (β = 0.026, < 0.001) and prospectively (β = 0.010, < 0.001). Reallocating 30 min/day of sedentary time into VPA was positively cross-sectionally (β = 0.780, < 0.001) and prospectively (β = 0.303, < 0.05) associated with CRF. Conversely, relocating 30-minutes of sedentary time into 30 minutes of LPA and MPA was not associated with CRF. These results suggest that reallocating an equal amount of time from sedentary into VPA is cross-sectional and prospectively associated with a favourable CRF.  相似文献   

3.
The aim was to assess the relationship between school rhythm and physical activity (PA) in adolescents. The study included 2024 adolescents (12.5–17.4 years). Participants wore an accelerometer for 7 days. A short school rhythm was defined as a short time at school with short recesses and less time in teaching per day (Group 1). A long school rhythm was defined as a longer time at school with more time in teaching and recess (Group 2). Adolescents in Group 1 performed less moderate to vigorous PA (MVPA) than those in Group 2 per week (P < .0001), especially during school days (recess: 3.9 ± 4.0 vs. 9.8 ± 7.9 min · day?1; < .0001; teaching hours: 14.5 ± 9.8 vs. 19.1 ± 12.0 min · day?1; < .0001). Adolescents in Group 1 were less likely to meet the PA recommendations than were adolescents in Group 2: 30.7% vs. 34.1% (< .0001). During school days, the percentage of adolescents who spent more than 2 h · day?1 in sedentary activities was greater in the Group 1 (< .001). Our results suggest that leisure-time out-of-school hours is used mainly for sedentary activities, and that school time provides a good opportunity for promoting PA.  相似文献   

4.
Physical education has been highlighted as an important environment for physical activity promotion, however, to our knowledge there are no previous studies examining the contribution of physical education to daily accelerometer-measured physical activity and non sedentary behaviour. The purpose was to compare the accelerometer-measured physical activity and sedentary behaviour between physical education, non-physical education and weekend days in adolescents. Of the 394 students from a Spanish high school that were invited to participate, 158 students (83 boys and 75 girls) aged 13–16 years were analyzed (wear time ≥ 600 min). Participants’ physical activity and sedentary behaviour were objectively-measured by GT3X+ accelerometers during physical education (one session), non-physical education and weekend days. Results indicated that overall adolescents had statistically significant greater physical activity levels and lower values of sedentary behaviour on physical education days than on non-physical education and weekend days (e.g., moderate-to-vigorous physical activity = 71, 54 and 57 min; sedentary = 710, 740 and 723 min) (p < 0.05). Physical education contributes significantly to reducing students’ daily physical inactivity and sedentary behaviour. Increasing the number of physical education classes seems to be an effective strategy to reduce the high current prevalence of physical inactivity and sedentary behaviour in adolescence.  相似文献   

5.
Previous nationally-representative research in Scotland found a j-shaped relationship between age and leisure sedentary time (ST): a decrease from young to middle-age, before rising steeply in older-age. This study investigated the effects of age and sex on weekday (including work) ST for all adults and stratified by work-status, and on weekend day ST. Differences in the relative contributions of component behaviours were also investigated. Responses from 14,367 adult (≥16 years) 2012–14 Scottish Health Survey participants were analysed using linear regressions. We found no j-shaped relationship between age and weekday ST. Instead, only 16–24 year olds reported lower levels than those over 75 years (6.6 (95% CI: 6.3–6.9) compared to 7.4 (95% CI: 7.2–7.6) hours/day; p < 0001). The j-shape was only evident in the stratified analysis amongst women not in work, and for weekend day ST for all groups. For those in work, work ST accounted for 45% of weekday ST. Television/screen ST made up over half of leisure ST on weekdays and weekend days, regardless of sex, age, or work-status. These results challenge our understanding of how ST varies by age. Interventions to reduce ST should consider differences in the relative contributions of ST behaviours by age and work-status.  相似文献   

6.
This study tests calibration models to re-scale context-specific physical activity (PA) items to accelerometer-derived PA. A total of 195 4th–12th grades children wore an Actigraph monitor and completed the Physical Activity Questionnaire (PAQ) one week later. The relative time spent in moderate-to-vigorous PA (MVPA%) obtained from the Actigraph at recess, PE, lunch, after-school, evening and weekend was matched with a respective item score obtained from the PAQ’s. Item scores from 145 participants were calibrated against objective MVPA% using multiple linear regression with age, and sex as additional predictors. Predicted minutes of MVPA for school, out-of-school and total week were tested in the remaining sample (n = 50) using equivalence testing. The results showed that PAQ β-weights ranged from 0.06 (lunch) to 4.94 (PE) MVPA% (P < 0.05) and models root mean square error ranged from 4.2% (evening) to 20.2% (recess). When applied to an independent sample, differences between PAQ and accelerometer MVPA at school and out-of-school ranged from ?15.6 to +3.8 min and the PAQ was within 10–15% of accelerometer measured activity. This study demonstrated that context-specific items can be calibrated to predict minutes of MVPA in groups of youth during in- and out-of-school periods.  相似文献   

7.
This study examined how children’s physical activity levels during recess and lunchtime and the contribution of recess and lunchtime to daily physical activity differed across seasons. Three hundred and twenty-six children aged 8–11 years from Australia participated. Physical activity was measured every 15-seconds using hip-mounted ActiGraph accelerometers for 7 consecutive days during the winter (n = 246), spring (n = 211), summer (n = 161) and autumn terms (n = 139). Data were collected 2012–2013. Time spent in light- (LPA) moderate- (MPA), vigorous- (VPA), and moderate- to vigorous-intensity physical activity (MVPA) during recess and lunchtime were calculated. Longitudinal data were analysed using multilevel analyses and adjusted for potential confounders. The results showed that compared to winter, children engaged in significantly less MVPA and VPA in spring and summer during lunchtime (p < 0.05). No significant changes were observed during recess. The contribution of lunchtime to VPA and MVPA significantly decreased in spring and summer compared to winter (p < 0.05). Children’s lunchtime physical activity levels decreased between winter and spring and summer, with greater declines observed in VPA. Strategies to increase physical activity levels in every season are needed during lunchtime, with a greater emphasis on warmer months.  相似文献   

8.
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.  相似文献   

9.
Background:This study examined the volume and patterns of physical activity(PA) and sedentary time(ST) across different segments of the week among boys and girls.Methods:A total of 188 children aged 7-12 years wore a wrist-mounted ActiGraph GT3 X+accelerometer for 7 days.Time spent in PA and ST was calculated using ActiLife software.The mean number of minutes of light PA,moderate PA,vigorous PA,moderate-to-vigorous PA(MVPA),and ST were calculated per weekday(before school,during school,and after school) and per weekend day(morning and afternoon-evening).Results:After school represented the greatest accumulation of ST compared with before school and during school segments.Boys engaged in225.4 min/day of ST(95% confidence interval(CI):216-235),and girls engaged in 222.2 min/day of ST(95%CI:213-231).During school,boys engaged in significantly more MVPA than girls(46.1 min/day(95%CI:44-48) vs.40.7 min/day(95%CI:39-43)).Across the whole weekday,boys participated in significantly more MVPA than girls(103.9 min/day(95%CI:99-109) vs.95.7 min/day(95%CI:90-101)).The weekend afternoon—evening segment represented the larger accumulation of ST,where boys were significantly more sedentary than girls(367.5 min/day(95%CI:353-382) vs.339.8 min/day(95%CI:325-355),respectively).Conclusion:Our findings suggest that children are highly sedentary and spend little of their time in school in MVPA,especially girls.Routine breaks in school elicit increases in light PA and MVPA.Future work should consider the use of more active breaks within school time to encourage PA and reduce ST.  相似文献   

10.
The objective of this study was to evaluate gross motor competence and growth spurt in Canadian youth. Eighty-two children (38 boys, 44 girls) were assessed over a time period of five years. Growth rate was measured quarterly; motor competence was evaluated once per year using the Bruininks-Oseretsky Test of Motor Proficiency. Peak height velocity (PHV) occurred at a significantly younger age in the girls (11.3 ± 0.4 years) than the boys (13.4 ± 0.3 years; < .001), and growth rate during PHV was significantly greater in the boys than the girls (2.8 ± 1.3 vs. 2.0 ± 0.7 cm/quarter; = .003). Gross motor competence outcomes were significantly above the North American normative scores (< .05) over the measured time period. After the occurrence of PHV, strength, strength/agility, and gross motor skill significantly decreased in girls (< .01), and running speed/agility significantly decreased in boys (< .05). This finding emphasizes that motor competence in pre-adolescent children may suddenly decrease after their growth spurt.  相似文献   

11.
The aims of this study were: (1) to observe participation in moderate-to-vigorous physical activity (MVPA) during school recess periods; (2) to determine the relative importance of physical activity during recesses to overall daily physical activity; and (3) to examine differences in physical activity between the sexes during unstructured recess periods. The participants were 22 school children (10 boys, 12 girls) aged 8?–?10 years (mean = 8.9, s = 0.7) in the third and fourth grades. Daily totals for the physical activity variables were calculated by summing the values for each hour of 14?h of physical activity measurements (08:00 to 22:00?h). Recess times (minutes) were as follows: morning 10:30 to 11:00?h and afternoon 15:30 to 16:00?h. We did not differences between boys and girls in daily total accelerometer counts or the overall time spent in MVPA. However, girls were significantly (P <?0.05) more involved (38%) in MVPA during recess time than boys (31%). Participation in MVPA during recess contributes significantly more (P <?0.05) for girls (19%) than boys (15%) to the total amount of physical activity suggested by international health-related physical activity guidelines, while the percentage of time engaged in MVPA during recess time at school accounts for a small amount of the daily MVPA (6% for boys and 8% for girls). The results of this study suggest that school recess time is an important setting to promote MVPA and contributes to daily physical activity in young children, especially in girls.  相似文献   

12.
This study assessed children’s physical activity (PA) levels derived from wrist-worn GENEActiv and hip-worn ActiGraph GT3X+ accelerometers and examined the comparability of PA levels between the two devices throughout the segmented week. One hundred and twenty-nine 9–10-year-old children (79 girls) wore a GENEActiv (GAwrist) and ActiGraph GT3X+ (AGhip) accelerometer on the left wrist and right hip, respectively, for 7 days. Mean minutes of light PA (LPA) and moderate-to-vigorous PA (MVPA) per weekday (whole-day, before-school, school and after-school) and weekend day (whole-day, morning and afternoon–evening) segments were calculated, and expressed as percentage of segment time. Repeated measures analysis of variance examined differences in LPA and MVPA between GAwrist and AGhip for each time segment. Bland–Altman plots assessed between-device agreement for LPA and MVPA for whole weekday and whole weekend day segments. Correlations between GAwrist and AGhip were weak for LPA (= 0.18–0.28), but strong for MVPA (= 0.80–0.86). LPA and MVPA levels during all weekday and weekend day segments were significantly higher for GAwrist than AGhip (< 0.001). The largest inter-device percent difference of 26% was observed in LPA during the school day segment. Our data suggest that correction factors are needed to improve raw PA level comparability between GAwrist and AGhip.  相似文献   

13.
Abstract

Levels of physical inactivity and sedentary behaviour among English and Spanish youth are high and vary within different regions of each country. Little though is known about these during specific periods of the day. The purpose of this study was to describe physical activity (PA) and sedentary time during segments of the day and week, and compare these critical contexts between youth in the Liverpool and Madrid areas of England and Spain, respectively. PA was objectively assessed in 235 Liverpool- and 241 Madrid youth (aged 10–14 years) who wore accelerometers for seven consecutive days. Minutes of sedentary time, moderate PA, vigorous PA and moderate-to-vigorous physical activity (MVPA) were calculated for weekdays, weekend days, school time, non-school time and after-school. Between-country differences were analysed using analysis of covariance (ANCOVA). Madrid youth spent significantly more time in sedentary activities than their Liverpool counterparts. Madrid youth engaged in more minutes of moderate intensity physical activity (MPA) than Liverpool youth during weekdays, school time and non-school time (P<0.01). Liverpool children recorded more time in vigorous physical activity (VPA) than Madrid peers during week days and weekend days (P<0.01) and during school time and after-school periods (P <0.01). The MVPA was significantly higher among Madrid youth during non-school time (P<0.01). Around 25% of all youth achieved recommended levels of MVPA. Low levels of MVPA and systematic differences in sedentary time, MPA and VPA exist between Liverpool and Madrid youth. Interventions targeted at the least-active children during weekends, after-school and non-school periods within the cultural contexts common to each city are required.  相似文献   

14.
This study explored the validity of ActiGraph-determined sedentary time (<50 cpm, <100 cpm, <150 cpm, <200 cpm, <250 cpm) compared with the activPAL in a free-living sample of bus drivers. Twenty-eight participants were recruited between November 2013 and February 2014. Participants wore an activPAL3 and ActiGraph GT3X+ concurrently for 7 days and completed a daily diary. Time spent sedentary during waking hours on workdays, non-workdays, during working-hours, and non-working hours were compared between instruments. During working hours, all ActiGraph cut-points significantly underestimated sedentary time (p < 0.05), whereas during non-working hours the <50 cpm cut-point demonstrated the closest agreement (ActiGraph sedentary time: 250 ± 75 minutes versus activPAL sedentary time: 236 ± 65 minutes). Receiver operating characteristic analyses revealed that on workdays and non-workdays the ActiGraph cut-points exhibited relatively low sensitivity (all <0.62) and specificity (all <0.49) values. The use of the ActiGraph to measure sedentary time in this understudied, highly sedentary and at risk occupational group is not recommended.  相似文献   

15.
Overtraining syndrome (OTS) is caused by an imbalance between training, nutrition and resting, and leads to decreased performance and fatigue; however, the precise underlying triggers of OTS remain unclear. This study investigated the body composition, metabolism, eating, sleeping patterns and mood states among participants with OTS. Selected participants were divided into OTS-affected athletes (OTS, n = 14), healthy athletes (ATL, n = 25), and healthy non-physically active controls (NCS, n = 12). Compared to ATL, OTS showed decreased sleep quality (p = 0.004); increased duration of work or study (p < 0.001); decreased libido (p = 0.024); decreased calorie (p < 0.001), carbohydrate (p < 0.001) and protein (p < 0.001) intakes; decreased mood states (p < 0.001); decreased basal metabolic rate (p = 0.013) and fat burning (p < 0.001); increased body fat (p = 0.006); decreased muscle mass (p = 0.008); and decreased hydration (p < 0.001). Levels were similar between OTS and NCS, except for worsened fatigue (p < 0.001) and vigour (p = 0.001) in OTS. Reduced calorie intake, worsened sleep, and increased cognitive activity are likely OTS triggers. OTS appears to induce dehydration, increase body fat, decrease libido, and worsen mood.  相似文献   

16.
The purposes of this study were to examine how fitness at the baseline could predict both academic achievement and academic achievement changes one school year in advance. A total of 194 adolescents (mean age: 14.15 ± 0.97 years old, 112 boys) who attended secondary school participated in our study. Cardiorespiratory fitness was measured with the 20 m endurance shuttle-run test. We also assessed the lower-limbs muscular strength with the standing long jump test and flexibility with the sit-and-reach test. The academic achievement was assessed by school grades. We performed linear regression analyses. Additionally, we examined the relationship between fitness and changes in the academic performance following the same statistical methodology. Cardiorespiratory fitness was positively associated with mathematics one school year in advance (p = 0.025). Cardiorespiratory fitness was also positively associated with changes in Spanish language (p = 0.005), mathematics (p = 0.023), and the grade point average (p = 0.006). Muscular strength was also positively associated with changes in Spanish language (p = 0.040) and mathematics (p = 0.010), while flexibility was associated with changes in Spanish language (p = 0.039) and the grade point average (0.027). Our results suggest that cardiorespiratory fitness was positively associated with academic achievement in adolescents.  相似文献   

17.
We studied differences in physical activity (PA), sedentary behaviour (SB), and the types of PA and SB between Finnish girls and boys and children from different socioeconomic backgrounds (SES). We assessed PA, SB, parental education, and household income using detailed questionnaires in a representative population sample of 486 children (238 girls, 248 boys) aged 6–8 years. Girls spent on average 1.7 h/day and boys 2.0 h/day in total PA (p?=?0.002). Altogether 66% of girls and 54% of boys had less than 2 h of total PA per day (p?=?0.012). Girls had lower levels of unsupervised PA (45 vs. 54 min/day, p?=?0.001), supervised PA (1.5 vs. 1.9 h/week, p?=?0.009), and PA during school recess (1.8 vs. 1.9 h/week, p?=?0.032) than boys. Girls had higher levels of total SB (3.8 vs. 3.4 h/day, p?=?0.015) but lower levels of screen-based SB (1.5 vs. 1.9 h/day, p?<?0.001) than boys. Lower parental education and household income were associated with lower levels of supervised PA in girls (p?=?0.011 and p?=?0.008, respectively) and in boys (p?=?0.006 and p?=?0.003, respectively). Lower parental education and household income were also related to higher levels of screen-based SB in boys (p?=?0.005 and p?<?0.001, respectively) but not in girls. Girls have lower levels of total, unsupervised, and supervised PA, PA during recess, and screen-based SB but higher levels of total SB than boys. Lower parental education and household income are associated with lower levels of supervised PA in both genders and higher levels of screen-based SB in boys.  相似文献   

18.
ABSTRACT

This study aimed to investigate between- and within-team changes in workload [PlayerLoad (PL), training impulse (TRIMP) and session rate of perceived exertion training load (sRPE-TL)], readiness [heart rate variability (HRV)], and physical performance [20-m sprint test (including 10-m split time), countermovement jump (CMJ) and yo-yo intermittent recovery test level 1 (YYIR1)] during 3-week intensified preparation periods in female, national Under18 (n = 12, age = 18.0 ± 0.5y, stature = 180.4 ± 7.5 cm, body mass = 72.7 ± 9.3 kg) and Under20 (n = 12, age = 19.6 ± 0.8y, stature = 178.6 ± 6.4 cm, body mass = 68.0 ± 5.9 kg) basketball teams. Under18 team revealed small-to-moderate statistically significantly higher values in workload [PL: p = 0.010; ES = Small; TRIMP: p = 0.004; ES = Moderate; sRPE-TL: p < 0.001; ES = Moderate] and moderately lower readiness values (p = 0.023; ES = Moderate) compared to Under20. Within-team analysis showed no differences in workload in Under20 and statistically significant reduction (p < 0.05) in Week3 (taper period) in Under18. Pre- and post-preparation changes showed Under18 increasing only YYIR1 performance (p < 0.001; ES = Very large). Differently, Under20 statistically improved in 10-m split time (p = 0.003; ES = Moderate), CMJ (p = 0.025; ES = Moderate) and YYIR1 (p < 0.001; ES = Large). A constant adequate workload positively benefits players’ readiness and physical performances during short intensified preparation periods. Conversely, using high workload with periodization strategies encompassing short overload and taper phases induced positive changes on players’ aerobic performance, lower readiness values and no changes in anaerobic performances.  相似文献   

19.
This review assembles pedometry literature focused on youth, with particular attention to expected values for habitual, school day, physical education class, recess, lunch break, out-of-school, weekend, and vacation activity. From 31 studies published since 1999, we constructed a youth habitual activity step-curve that indicates: (a) from ages 6 to 18 years, boys typically take more steps per day than girls; (b) for both sexes the youngest age groups appear to take fewer steps per day than those immediately older; and (c) from a young age, boys decline more in steps per day to become more consistent with girls at older ages. Additional studies revealed that boys take approximately 42–49% of daily steps during the school day; girls take 41–47%. Steps taken during physical education class contribute to total steps per day by 8.7–23.7% in boys and 11.4–17.2% in girls. Recess represents 8–11% and lunch break represents 15–16% of total steps per day. After-school activity contributes approximately 47–56% of total steps per day for boys and 47–59% for girls. Weekdays range from approximately 12,000 to 16,000 steps per day in boys and 10,000 to 14,000 steps per day in girls. The corresponding values for weekend days are 12,000–13,000 steps per day in boys and 10,000–12,000 steps per day in girls.  相似文献   

20.
The aims of this study were: (1) to observe participation in moderate-to-vigorous physical activity (MVPA) during school recess periods; (2) to determine the relative importance of physical activity during recesses to overall daily physical activity; and (3) to examine differences in physical activity between the sexes during unstructured recess periods. The participants were 22 school children (10 boys, 12 girls) aged 8 - 10 years (mean = 8.9, s = 0.7) in the third and fourth grades. Daily totals for the physical activity variables were calculated by summing the values for each hour of 14 h of physical activity measurements (08:00 to 22:00 h). Recess times (minutes) were as follows: morning 10:30 to 11:00 h and afternoon 15:30 to 16:00 h. We did not differences between boys and girls in daily total accelerometer counts or the overall time spent in MVPA. However, girls were significantly (P < 0.05) more involved (38%) in MVPA during recess time than boys (31%). Participation in MVPA during recess contributes significantly more (P < 0.05) for girls (19%) than boys (15%) to the total amount of physical activity suggested by international health-related physical activity guidelines, while the percentage of time engaged in MVPA during recess time at school accounts for a small amount of the daily MVPA (6% for boys and 8% for girls). The results of this study suggest that school recess time is an important setting to promote MVPA and contributes to daily physical activity in young children, especially in girls.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号