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1.
The present study examined the sex-specific associations of moderate and vigorous physical activity (VPA) with physical fitness in 300 Japanese adolescents aged 12–14 years. Participants were asked to wear an accelerometer to evaluate physical activity (PA) levels of various intensities (i.e. moderate PA (MPA), 3–5.9 metabolic equivalents (METs); VPA, ≥6 METs; moderate to vigorous PA (MVPA), ≥3 METs). Eight fitness items were assessed (grip strength, bent-leg sit-up, sit-and-reach, side step, 50?m sprint, standing long jump, handball throw, and distance running) as part of the Japanese standardised fitness test. A fitness composite score was calculated using Japanese fitness norms, and participants were categorised according to their score from category A (most fit) to category E (least fit), with participants in categories D and E defined as having low fitness. It was found that for boys, accumulating more than 80.7?min/day of MVPA may reduce the probability of low fitness (odds ratio (ORs) [95% confidence interval (CI)]?=?0.17 [0.06–0.47], p?=?.001). For girls, accumulating only 8.4?min of VPA could reduce the likelihood of exhibiting low fitness (ORs [95% CI]?=?0.23 [0.05–0.89], p?=?.032). These results reveal that there are sex-specific differences in the relationship between PA and physical fitness in adolescents, suggesting that sex-specific PA recommendation may be needed to improve physical fitness in adolescents.  相似文献   

2.
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   

3.
This study examined differences in physical activity (PA) estimates provided from raw and counts processing methods. One hundred and sixty-five children (87 girls) wore a hip-mounted ActiGraph GT3X+ accelerometer for 7 days. Data were available for 129 participants. Time in moderate PA (MPA), vigorous PA (VPA) and moderate-vigorous PA (MVPA) were calculated using R-package GGIR and ActiLife. Participants meeting the wear time criteria for both processing methods were included in the analysis. Time spent in MPA (?21.4 min.d?1, 95%CI ?21 to ?20) and VPA (?36 min.d?1, 95%CI ?40 to ?33) from count data were higher (P < 0.001) than raw data. Time spent in MVPA between the two processing methods revealed significant differences (All P < 0.001). Bland-Altman plots suggest that the mean bias for time spent in MPA, VPA and MVPA were large when comparing raw and count methods. Equivalence tests showed that estimates from raw and count processing methods across all activity intensities lacked equivalence. Lack of equivalence and poor agreement between raw and count processing methods suggest the two approaches to estimate PA are not comparable. Further work to facilitate the comparison of findings between studies that process and report raw and count physical activity data may be necessary.  相似文献   

4.
Accelerometry is the gold standard for field-based physical activity assessment in children; however, the plethora of devices, data reduction procedures, and cut-points available limits comparability between studies. This study aimed to compare physical activity variables from the ActiGraph GT3X+ and Actical accelerometers in children under free-living conditions. A cross-sectional study of 379 children aged 9–11 years from Ottawa (Canada) was conducted. Children wore the ActiGraph GT3X+ and Actical accelerometers on the hip simultaneously for 7 consecutive days (24-h protocol). Moderate-to-vigorous (MVPA), vigorous (VPA), moderate (MPA), and light (LPA) physical activity, as well as sedentary time, (SED) were derived using established data reduction protocols. Excellent agreement between devices was observed for MVPA (ICC = 0.73–0.80), with fair to good agreement for MPA, LPA and SED, and poor agreement for VPA. Bland-Altman plots showed excellent agreement for MVPA, LPA, and SED, adequate agreement for MPA, and poor agreement for VPA. MVPA derived from the Actical was 11.7% lower than the ActiGraph GT3X+. The ActiGraph GT3X+ and Actical are comparable for measuring children’s MVPA. However, comparison between devices for VPA, MPA, LPA, and SED are highly dependent on data reduction procedures and cut-points, and should be interpreted with caution.  相似文献   

5.
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, p < 0.001) and prospectively (β = 0.010, p < 0.001). Reallocating 30 min/day of sedentary time into VPA was positively cross-sectionally (β = 0.780, p < 0.001) and prospectively (β = 0.303, p < 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   

6.
Abstract

The purpose of the present investigation was to examine the relationship between the accumulation of 1000 steps in 10 minutes (1K) and 3000 steps in 30 minutes (3K) with the amount and intensity of daily physical activity. Thirty-three adults (16 males and 17 females, 53 ± 19 years) wore an accelerometer (Lifecorder) for seven consecutive days in order to determine the number of steps and the time spent in physical activity at light intensity (LPA), moderate intensity (MPA), vigorous intensity (VPA) and moderate to vigorous intensity (MVPA). Furthermore, based on the minute-by-minute stepping rate, the number, intensity and duration of walking bouts (1K and 3K) were evaluated. The daily number of steps, LPA, MPA and VPA were significantly higher on the days with 1K or 3K compared with that observed on the days without 1K or 3K (P <0.05). The duration of 1K was not found to be correlated with an MVPA >10 minutes. An MVPA >10 minutes was less than 2 min · day?1 on the days with 1K or 3K. Therefore, it is doubtful that the concept of cadence is an alternative indicator for the commonly used definition of MVPA. It remains unclear whether participation in 1K and 3K guarantees that an individual will meet the current MVPA guidelines.  相似文献   

7.
目的：探究体育课堂不同运动强度累积时间与体质健康之间的关系。方法：用Actigraph wGT3X-BT采集360名城区和郊区高中生40 minSB、LPA、MPA、VPA累积时间和7日总佩戴时间,并统一进行体质健康测试,运用SPSS23.0对各项指标进行相关分析、回归分析和等时替代分析。结果：（1）在体育课上高中男生MPA、VPA运动时间均显著高于女生,体质健康水平也存在显著性性别差异;（2） LPA运动时间与各项目（立定跳远除外）之间无关,SB、MPA、VPA运动时间与体质健康大部分项目之间均显著相关;（3）对于高中男生,VPA运动时间对立定跳远、引体向上、坐位体前屈,MPA运动时间对肺活量和1000m单独产生有益影响;LPA运动时间对立定跳远、引体向上、坐位体前屈,SB时间对1000m单独产生不利影响;在控制LPA运动时间后,VPA和MPA运动时间对相关体质健康的有益影响减弱;在等时替代LPA后,VPA和MPA运动时间对相关体质健康的有益影响增强;（4）对于高中女生,SB、LPA、MPA与VPA运动时间对体质健康各项目的单独和等时替代影响均不显著,在控制LPA后,SB时间显著提高女生50m速度。结论：目前上海市高中生体育课低于50% MVPA运动时间,MPA运动时间具有发展男生肺活量和1000m的特异性,VPA运动时间具有发展男生立定跳远、引体向上、坐位体前屈和50m的特异性,加速度计测量的课堂SB为肌肉力量和柔韧练习,但是高中女生体质健康的改善需要克服传统体育课程长期运动强度不足的负面效应。  相似文献   

8.
目的以客观测量的体力活动水平为基础,分析不同持续时间活动的频率及其占总活动时间的比例,从而掌握学龄前儿童体力活动簇集特征。方法根据知情、自愿原则,在上海市杨浦和宝山2个区共招募306名学龄前儿童为受试者,通过连续7 d佩戴加速度传感器ActiGraph GT3X+测量其日常体力活动水平,在此基础上将每次体力活动按强度和持续时间进行分类,并统计不同持续时间的活动平均每天出现的频率及其占总累积活动的比例。结果共有146名受试者[男85名,女61名;平均月龄为(57.7±5.0)月]7 d测量数据均有效,被纳入最终统计分析。发现采样间隔为1 s时,学龄前儿童平均每次体力活动持续时间≤4 s,且70%以上的中等强度和大强度体力活动持续时间为2~3 s。结论学龄前儿童体力活动以持续时间较短的零星活动为主。为准确测量学龄前儿童体力活动,特别是中到大强度体力活动水平,宜采用较短的加速度传感器采样间隔(如3 s或更短时间)。  相似文献   

9.
Abstract

This aim of this study was to compare the new Actigraph (GT1M) with the widely used Model 7164. Seven days of free-living physical activity were measured simultaneously using both the Model 7164 and GT1M in 30 Indian adolescents (mean age 15.8 years, s = 0.6). The GT1M was on average 9% lower per epoch than model 7164, thus a correction factor of 0.91 is suggested for comparison between the two monitors. The differences between monitors increased in magnitude with intensity of activity (P < 0.001) but remained randomly distributed (r = 0.01, P = 0.96). No significant difference was observed between monitors for time spent in moderate (P = 0.31) and vigorous (P = 0.34) physical activity when using the same epoch length. The Model 7164 classified less time as sedentary (P < 0.001) and more time as light-intensity activity (P < 0.001) than the GT1M. In conclusion, data from the GT1M can be compared with historical data using average counts per minute with a correction factor, and the two models might be comparable for assessing time spent in moderate to vigorous physical activity in children when using the same epoch length.  相似文献   

10.
Participation in youth sport is assumed to promote and contribute towards more physically active lifestyles among children and adolescents. The aim of this study was to examine inter-participant variability in objectively measured habitual physical activity (PA) behaviours and sedentary time among youth sport participants and their implications for health. One-hundred-and-eighteen male youth sport footballers (Mean ± s = 11.72 ± 1.60) wore a GT3X accelerometer for 7 days. Average daily PA [min · day?1, in light (LPA), moderate (MPA), vigorous (VPA) and combined moderate-to-vigorous (MVPA)] and sedentary time were calculated. Participants’ body mass index adjusted for age and sex (BMI–standard deviation score), per cent body fat (BF%), waist circumference and cardiorespiratory fitness were assessed. Results revealed that variability in daily PA behaviours and sedentary time (min · day?1) was associated with BMI–standard deviation score [VPA (?), MVPA (?)], BF% [sedentary time (+), VPA (?), MVPA (?)], waist circumference [sedentary time (+), LPA (?)] and cardiorespiratory fitness [sedentary time (?), MPA (+), VPA (+), MVPA (+)]. Whilst sedentary time and MVPA were not related to health outcomes independent of one another, associations with markers of adiposity and cardiorespiratory fitness were stronger for sedentary time. Sedentary time was also significantly positively related to waist circumference independent of VPA. Results demonstrate inter-participant variability in habitual PA and sedentary time among youth sport participants which holds implications for their health. Thus, promoting PA and, in particular, reducing sedentary time may contribute towards the prevention of adverse health consequences associated with a physically inactive lifestyle for children and adolescents active in the youth sport context.  相似文献   

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