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1.
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   

2.
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   

3.
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   

4.
BackgroundStructured vigorous physical activity (VPA) can improve cognitive control in children, but studies relating daily physical activity (PA) to cognitive control have yielded conflicting findings. While objectively measured daily PA summarizes all occurrences of PA within a registered period, a minimum duration of continuous PA is required for registration of a PA bout. Because brief bouts of high-intensity PA can account for a large proportion of children's daily activity-related energy expenditure, this study assessed whether daily and bouted VPA were selectively related to cognitive control in preadolescents relative to other PA intensities.MethodsA total of 75 children between the ages of 8 and 10 years (49% girls) wore an ActiGraph wGT3X+ on the hip for 7 days. The acceleration signal from the vertical axis was summarized over 1 s, 5 s, and 15 s epochs. Daily and bouted moderate PA, moderate-to-vigorous PA, and VPA were measured. PA bouts were expressed as the frequency and time spent in 2 different continuous PA bouts, one lasting ≥10 s and the other lasting ≥30 s at a given intensity. Inhibitory control was assessed using behavioral responses to a modified flanker task (mean reaction time (RTmean) and accuracy). Attentional resource allocation and cognitive processing speed were measured using the amplitude and latency of the P3 component of event-related brain potentials, respectively. Associations between PA, behavioral indices of inhibitory control, P3 amplitude, and latency were assessed using hierarchical regression models.ResultsDaily VPA was not related to RTmean or accuracy on either congruent or incongruent trials. In contrast, more time spent in VPA bouts lasting ≥30 s predicted shorter P3 latency across epochs and flanker congruencies (all β ≤ –0.24, all p ≤ 0.04). The associations between shorter P3 latency and the time spent in moderate-to-vigorous PA bouts lasting ≥30 s were less consistent and largely limited to congruent trials (congruent: β (–0.31, –0.34)). No significant associations were observed upon correction for false discovery rate.ConclusionThe pattern of uncorrected associations aligns with the dose–response literature and suggests that brief VPA bouts may yield the greatest benefits to cognitive processing speed in preadolescents. Future studies using measures of brain structure and function are needed to understand the mechanisms linking bouted VPA to neurocognitive function during childhood.  相似文献   

5.
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   

6.
This study compared children’s physical activity (PA) levels, the prevalence of children meeting current guidelines of ≥60 minutes of daily moderate to vigorous PA (MVPA), and PA-health associations using individually calibrated (IC) and empirical accelerometer cutpoints. Data from 75 (n = 32 boys) 10–12 year old children were included in this study. Clustered cardiometabolic (CM) risk, directly measured cardiorespiratory fitness (CRF), anthropometric and 7 day accelerometer data were included within analysis. PA data were classified using Froude anchored IC, Evenson et al. (Evenson, K. R., Catellier, D. J., Gill, K., Ondrak, K. S., &; McMurray, R. G. (2008). Calibration of two objective measures of physical activity for children. Journal of Sports Sciences, 26(14), 1557–1565. doi:10.1080/02640410802334196) (Ev) and Mackintosh et al. (Mackintosh, K. A., Fairclough, S. J., Stratton, G., &; Ridgers, N. D. (2012). A calibration protocol for population-specific accelerometer cutpoints in children. PLoS One, 7(5), e36919. doi:10.1371/journal.pone.0036919) (Mack) cutpoints. The proportion of the cohort meeting ≥60mins MVPA/day ranged from 37%-56% depending on the cutpoints used. Reported PA differed significantly across the cutpoint sets. IC LPA and MPA were predictors of CRF (LPA: standardised β = 0.32, p = 0.002, MPA: standardised β = 0.27 p = 0.013). IC MPA also predicted BMI Z-score (standardised β = ?0.35, p = 0.004). Ev VPA was a predictor of BMI Z-score (standardised β = ?0.33, p = 0.012). Cutpoint choice has a substantial impact on reported PA levels though no significant associations with CM risk were observed. Froude IC cutpoints represent a promising approach towards classifying children’s PA data.  相似文献   

7.
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   

8.
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   

9.
The GT3X+ worn at the wrist promotes greater compliance than at the hip. Minutes in SB and PA calculated from raw accelerations at the hip and wrist provide contrasting estimates and cannot be directly compared.

Wear-time for the wrist (15.6 to 17.4 h.d?1) was greater than the hip (15.2 to 16.8 h.d?1) across several wear-time criteria (all P < 0.05). Moderate-strong associations were found between time spent in SB (r = 0.39), LPA (r = 0.33), MPA (r = 0.99), VPA (r = 0.82) and MVPA (r = 0.81) between the two device placements (All P < 0.001). The wrist device detected more minutes in LPA, MPA, VPA and MVPA whereas the hip detected more SB (all P = 0.001). Estimates of time in SB and all activity outcomes from the wrist and hip lacked equivalence.

One hundred and eighty-eight 9–12-year-old children wore a wrist- and hip-mounted accelerometer for 7 days. Data were available for 160 (hip) and 161 (wrist) participants. Time spent in SB and PA was calculated using GGIR.

This study examined the compliance of children wearing wrist- and hip-mounted ActiGraph GT3X+ accelerometers and compared estimates of sedentary behaviour (SB) and physical activity (PA) between devices.  相似文献   

10.
BackgroundRegular physical activity (PA) is an important behavior in improving sleep health. However, the short-term effects of PA on sleep are still controversial. This study aimed to verify the effect of different intensities of PA practiced in different periods of the day on the subsequent sleep night in a population-based cohort of young adults.Methods: Prospective analyses were conducted for PA performed during the day and its effect on the following sleep night using data from the 22-year follow-up of the 1993 Pelotas Birth Cohort in Brazil (mean age of participants = 22.6 years). Wrist-worn accelerometry was used to measure both PA and sleep parameters. Regarding intensity, we analyzed the sleep effect of light PA (LPA), moderate PA, and vigorous PA, stratified by sex. Sleep variables were sleep time window (STW; the difference between sleep onset and sleep end), total sleep time (TST; the sum of minutes classified as sleep in STW), and sleep percent (SP; SP = (TST/STW); expressed in percentage). We performed generalized estimating equations using Stata software.Results: The means of STW, TST, and SP were 443.6 min/day, 371.1 min/day, and 84%, respectively. Time spent in moderate PA and vigorous PA in the morning and afternoon was not associated with sleep variables. Among men, 10 min/day of morning LPA increased TST by 2.56 min/day. Among women, 10 min/day of morning LPA increased SP by 0.15 percentage points. Afternoon LPA also increased SP by 0.09 percentage points for women. Night PA seems to have an inverse effect on sleep variables for any intensity and both sexes.Conclusion: The effect of PA on sleep health is intrinsically related to the period of the day in which it is performed. The effect magnitude is different between sexes. For better sleep health, it is preferable that PA be performed during the day.  相似文献   

11.
This study developed and validated a vector magnitude (VM) two-regression model (2RM) for use with an ankle-worn ActiGraph accelerometer. For model development, 181 youth (mean ± SD; age, 12.0 ± 1.5 yr) completed 30 min of supine rest and 2–7 structured activities. For cross-validation, 42 youth (age, 12.6 ± 0.8 yr) completed approximately 2 hr of unstructured physical activity (PA). PA data were collected using an ActiGraph accelerometer, (non-dominant ankle) and the VM was expressed as counts/5-s. Measured energy expenditure (Cosmed K4b2) was converted to youth METs (METy; activity VO2 divided by resting VO2). A coefficient of variation (CV) was calculated for each activity to distinguish continuous walking/running from intermittent activity. The ankle VM sedentary behavior threshold was ≤10 counts/5-s, and a CV≤15 counts/5-s was used to identify walking/running. The ankle VM2RM was within 0.42 METy of measured METy during the unstructured PA (P > 0.05). The ankle VM2RM was within 5.7 min of measured time spent in sedentary, LPA, MPA, and VPA (P > 0.05). Compared to the K4b2, the ankle VM2RM provided similar estimates to measured values during unstructured play and provides a feasible wear location for future studies.  相似文献   

12.
Abstract

Performing physical activity is considered health promoting but may induce a need for subsequent rest periods. This study aimed to determine the within-day interactions between vigorous physical activity (VPA) and sedentary behaviour (SB) in participants with low cardiorespiratory fitness. We tested the hypothesis that VPA is associated with a temporary subsequent increase in SB. One week of accelerometer data containing a minimum of one 10-min bout of VPA from 62 participants with low cardiorespiratory fitness (31–50 years old) were obtained from the MILE study. A comparison of SB was made between days with a bout of VPA and days without (control). Due to a positive association between VPA and number and duration of sedentary bouts, the time accumulated in both uninterrupted and total sedentary bouts were 27 (95% CI, 10–45)?min and 29 (95% CI, 9–50)?min higher on VPA days compared to control days (P?<?0.05). Our results indicate that in participants with low cardiovascular fitness, unprompted VPA is positively associated with an increase in subsequent sedentary time. We propose that such VPA-associated sedentary time may be viewed as part of a healthy activity pattern.  相似文献   

13.
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   

14.
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   

15.
The purpose of this study was to determine whether taking 10,000 steps in a day is equivalent to meeting the current minimum physical activity guidelines of accumulating at least 30 min of moderate physical activity (IMPA). Fifty-nine women ages 20-65 years wore a pedometer and accelerometer concurrently on their right hip for 1 day. There were no differences in the age, body mass index, or the amount of time the pedometers and accelerometers were worn between the 10K+ and the < 10K groups. The 10K+ group accumulated significantly more steps and minutes of MPA than the < 10K group (M = 13,084 steps, SD = 2,603 vs. M = 7,518 steps, SD = 1,956; and M = 62.1 min, SD = 27.7 vs. M = 38.8 min, SD = 18.9; p < .05). A 2 x 2 chi-square analysis demonstrated no difference between the proportions of 10K and < 10K participants who met the step goal, when all minutes of MPA accumulated throughout the day were considered (chi2 = 1.8, df = 1, p = .175). When only continuous bouts of MPA lasting > 5 min and > 10 min were considered, a significantly greater proportion of 10K participants met the current physical activity guidelines than the < 10K participants (chi2 = 11.5, df = 1, p = .001, and chi2 = 5.9, df = 1, p = .015, respectively). Our finding, suggest that individuals who accumulate 10,000 steps/day are more likely to meet the current physical activity guidelines by engaging in the length of bouts promoted by the Centers for Disease Control and Prevention and the American College of Sports Medicine (Pate et al., 1995) and the US Surgeon General (U.S. Department of Health and Human Services, 1996). However, the data also reveal that accumulating 10,000 steps/day does not guarantee meeting the guidelines in the bout lengths documented to confer the health benefits of physical activity.  相似文献   

16.
BackgroundOutdoor physical activity (PA) brings important health benefits, but exposure to polluted air increases health risks. This study aimed to quantify the tradeoff of PA under fine particulate matter (PM2.5) air pollution by estimating the optimal PA duration under various pollution levels.MethodsA risk-benefit analysis was performed to estimate the optimal outdoor moderate-intensity PA (MPA) duration under varying PM2.5 concentrations.ResultsAn inverse nonlinear relationship was identified between optimal MPA duration and background PM2.5 concentration levels. When background PM2.5 concentration increased to 186 µg/m3, the optimal outdoor MPA duration decreased to 2.5 h/week, the minimum level recommended by current PA guidelines. When background PM2.5 concentration further increased to 235 µg/m3, the optimal outdoor MPA duration decreased to 1 h/week. The relationship between optimal MPA duration and background PM2.5 concentration levels was stronger when exercising at a location closer to a source of air pollution. Compared to the general adult population, adults aged 60 years and older had substantially steeper curves—the optimal outdoor MPA duration decreased to 2.5 h/week when background PM2.5 concentration reached 45 µg/m3.ConclusionThe health benefit of outdoor MPA by far outweighs the health risk of PM2.5 pollution for the global average urban background concentration (22 μg/m3). This modeling study examined a single type of air pollutant and suffered from measurement errors and estimation uncertainties. Future research should examine other air pollutants and indoor PA, incorporate short- and mid-term health effects of MPA and air pollution into the risk-benefit analysis, and provide estimates specific for high-risk subgroups.  相似文献   

17.
The purpose of this study was to evaluate the influence of the location (ankle, hip, wrist) where an activity monitor (AM) is worn and of the minimum bout duration (BD) on physical activity (PA) variables during free-living monitoring. Study 1 participants wore AMs at three locations for 1 day while wearing the Intelligent Device for Energy Expenditure and Activity (IDEEA) system. Study 2 participants wore AMs at the same locations for 3 days. Variables included time (TMV, min/day) and AEE (AEEMV, kcal/day) for each monitor location and BD above a moderate-vigorous (MV) intensity. TMV and AEEMV in Study 1 were similar across AMs to IDEEA values at BD = 10 min, as was TMV in Study 2. This suggests that ankle-, wrist- and hip-worn AMs can provide similar PA outcome values during free-living monitoring at 10-min BDs.  相似文献   

18.
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   

19.
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   

20.
We hypothesised that habitual physical activity (PA) together with progressive endurance training contributes to the differences in training response (Δ[V(·)]O(2max)) in healthy and physically active male participants. Twenty volunteers (age 30±3 years and [V(·)]O(2max) 54±7 ml·kg?1·min?1) participated in an eight-week training program which included four to six heart rate-guided exercise sessions weekly. PA data over the whole period were collected by an accelerometer-equipped wristwatch. Individual relative intensities of endurance training and PA were separately determined by adjusting to [V(·)]O(2max) reserve and calculated as mean daily duration (min) of training and PA at light, moderate, high and very high intensity levels. [V(·)]O(2max) increased 6.4±4.1% (p < 0.0001) during the training period. Δ[V(·)]O(2max) correlated with the amount of habitual PA that was mainly of light intensity (r = 0.53, p = 0.016), but not with the duration of moderate, high or very high intensity PA (p = ns for all). Age, body mass index, and daily amount of training at any intensity level of exercise were not related to Δ[V(·)]O(2max) (p = ns for all). In conclusion, a high amount of habitual PA together with prescribed endurance training was associated with good training response in physically active males.  相似文献   

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