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1.
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   

2.
Abstract

The ActiGraph activity monitors have developed and newer versions of the ActiGraph accelerometers (GT1M, GT3X and GT3X +) are now available, including changes in hardware and software compared to the old version (AM7164). This is problematic as most of the validation and calibration work includes the AM7164. The aims of the study were to validate the ActiGraph GT1M during level and graded walking and to assess the potential underestimation of physical activity during cycling. Data were obtained from 20 participants during treadmill walking and ergometer cycling. Energy expenditure was measured via indirect calorimetry and used as the criterion method. Activity counts were highly correlated with energy expenditure during level walking (R2 = 0.82) and graded walking at 5% and 8% (R2 = 0.82 and R2 = 0.67, respectively). There was no linear relationship between activity counts and energy expenditure during cycling. The average activity counts for all data points during cycling was 1,157 counts per minute (CPM) (SD = 974), and mean energy expenditure was 5.0 metabolic equivalents. The GT1M is a valid tool for assessing walking across a wide range of speeds and gradients. However, there is no relationship between activity counts and energy expenditure during cycling and physical activity is underestimated by ≈73% during cycling compared to walking.  相似文献   

3.
Abstract

The aim of the study was to validate the self-report Multimedia Activity Recall for Children and Adolescents (MARCA) against accelerometry for the assessment of physical activity in New Zealand children. Participants (n = 716, 10–18 years) recalled 3–4 days of activity using the MARCA and underwent a partially overlapping 7-day accelerometry protocol during a national survey. Spearman correlation coefficients (ρ) assessed the association between accelerometer-derived counts per minute and MARCA-derived physical activity level and time in locomotion. Both data sources estimated time spent in light and moderate–vigorous physical activity. Association and agreement between methods for light physical activity and moderate–vigorous physical activity was assessed using correlations and Bland–Altman plots respectively, and paired t-tests conducted. Accelerometer-derived activity counts were moderately correlated with both MARCA-derived physical activity level and locomotion (ρ = 0.38, P < 0.0001). The correlation between methods was –0.14 for light physical activity and 0.28 for moderate–vigorous physical activity (P < 0.0001). The MARCA overestimated moderate–vigorous physical activity compared with accelerometry (120 min, P < 0.0001), which increased as moderate–vigorous physical activity time increased. Some sex and ethnicity (Māori [indigenous] versus non-Māori) differences were observed. Overall, the MARCA indicated moderate validity for assessment of physical activity level, locomotion and moderate–vigorous physical activity and poor validity for assessment of light physical activity. This was comparable to other self-report tools. The MARCA has utility for future large-scale research.  相似文献   

4.
Abstract

The purpose of this cross-sectional study was to examine the relationship between objectively measured physical activity, sedentary time, and cardiorespiratory fitness in a diverse sample of youth. Participants were recruited from three middle schools and completed assessments of height, weight, cardiorespiratory fitness, and wore an accelerometer for a minimum of four days. Hierarchical general linear models controlling for age, body mass index (BMI) percentile, and sex were used to evaluate the association of time (minutes per day) spent sedentary, and in moderate physical activity and vigorous physical activity with cardiorespiratory fitness (i.e., heart rate response [beats per minute], dependent variable). Results indicated age (β = –0.16, P < 0.05), BMI percentile (β = 0.33, P <0.05), being male (β = 0.17, P < 0.05), sedentary time (β = 0.11, P <0.05), moderate (β = –0.03, P > 0.05) and vigorous (β = –0.22, P < 0.05) physical activity explained 29% of the variance in cardiorespiratory fitness. Evaluation of fitness among high sedentary/high vigorous, high sedentary/low vigorous, low sedentary/low vigorous, and low sedentary/high vigorous groups (defined by the median split) showed that high levels of vigorous activity removed the detrimental effect of high levels of sedentary time on cardiorespiratory fitness. These analyses suggest that the negative impact of sedentary time can be mitigated by engaging in vigorous activity.  相似文献   

5.
Abstract

Although questionnaires are useful for evaluating patterns of physical activity in populations, they need to be validated. The objective of this study was to determine the validity and reliability of the long version of the International Physical Activity Questionnaire (IPAQ) in a Spanish population. The participants wore a uniaxial MTI Actigraph (Computer Science and Application, Inc.) accelerometer for 7 days and self-completed the IPAQ questionnaire twice, to assess its reliability. Criterion validity was assessed by comparing data from the IPAQ and data from the MTI. The final sample included 54 adults for the validity analysis and 66 adults for the reliability analysis. The correlations (r) between the IPAQ and the accelerometer were 0.29 (P<0.05) for total physical activity (MET · min?1 · day?1) versus total counts per minute, 0.30 (P<0.05) for time spent in vigorous activity, and 0.34 (P<0.05) for time spent sitting. The IPAQ showed a good reliability coefficient for total physical activity (r=0.82, P<0.05), vigorous activity (r=0.79, P<0.05), moderate activity (r=0.83, P<0.05), and time spent walking (r=0.73, P<0.05). Total time spent on work-related physical activities (r=0.92, P<0.05), on household-related activities (r=0.86, P<0.05), and leisure-time physical activities (excluding walking) (r=0.82, P<0.05) showed good reliability coefficients. Bland Altman analysis showed that discrepancies between the two methods increased with the amount of moderate and vigorous physical activity undertaken. In conclusion, the long version of the IPAQ has acceptable validity for the measurement of total and vigorous physical activity, and good reliability coefficients for application in the Spanish population studied here. The questionnaire showed poor validity for reporting moderate-intensity activity in this Spanish population.  相似文献   

6.
Abstract

The International Physical Activity Questionnaire (IPAQ) has been widely used to assess physical activity in healthy populations. The present study compared physical activity assessed by the long, self-administrated version of the International Physical Activity Questionnaire with physical activity assessed by accelerometry in patients with fibromyalgia. A total of 99 (five men) participants with fibromyalgia completed the International Physical Activity Questionnaire and wore an accelerometer for nine consecutive days. We analysed the correlations of physical activity expressed as min · day?1 of light, moderate, vigorous, and moderate to vigorous (MVPA) intensity, as well as time spent sitting, by the International Physical Activity Questionnaire and accelerometry by Spearman correlations. Bland and Altman plots were performed to verify the agreements between both instruments. The results showed weak yet significant correlations (Rs = 0.15–0.39, all P < 0.05) in all physical activity intensities between the two instruments, except for sedentary time. The highest correlations were observed for physical activity at home or in garden (Rs = 0.297, P < 0.01). The results suggest that the long self-administrated International Physical Activity Questionnaire is a questionable instrument to assess physical activity in patients with fibromyalgia. Therefore, physical activity measurement in fibromyalgia patients should not be limited solely to self-reported measures.  相似文献   

7.
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   

8.
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   

9.
Abstract

In this study, we evaluated agreement among three generations of ActiGraph? accelerometers in children and adolescents. Twenty-nine participants (mean age = 14.2 ± 3.0 years) completed two laboratory-based activity sessions, each lasting 60 min. During each session, participants concurrently wore three different models of the ActiGraph? accelerometers (GT1M, GT3X, GT3X+). Agreement among the three models for vertical axis counts, vector magnitude counts, and time spent in moderate-to-vigorous physical exercise (MVPA) was evaluated by calculating intraclass correlation coefficients and Bland-Altman plots. The intraclass correlation coefficient for total vertical axis counts, total vector magnitude counts, and estimated MVPA was 0.994 (95% CI = 0.989–0.996), 0.981 (95% CI = 0.969–0.989), and 0.996 (95% CI = 0.989–0.998), respectively. Inter-monitor differences for total vertical axis and vector magnitude counts ranged from 0.3% to 1.5%, while inter-monitor differences for estimated MVPA were equal to or close to zero. On the basis of these findings, we conclude that there is strong agreement between the GT1M, GT3X, and GT3X+ activity monitors, thus making it acceptable for researchers and practitioners to use different ActiGraph? models within a given study.  相似文献   

10.
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   

11.
The purpose of the study was to quantify the contributions of physical education, exergaming (active video games that also are a type of exercise), recess, lunch break and after-school time segments to children’s daily physical activity and sedentary behaviours. Participants were 138 second and third graders (71 girls) who attended 20-min recess and 75-min lunch time daily, 25-min regular physical education or exergaming-based classes being alternated daily. The after-school period was defined as 3:20–10:00pm. Physical activity was assessed via accelerometry and the dependent variables were children’s time spent in moderate-to-vigorous physical activity (MVPA), light physical activity and sedentary behaviour. Children’s percentages of time spent in MVPA (P < .001; except for the difference between exergaming and lunch break: P = .63), light physical activity (P < .001) and sedentary behaviour (P < .001) differed significantly across the time segments (i.e., physical education/exergaming, recess, lunch break and after-school). Additionally, children accumulated significantly more MVPA (t = 10.22, P < .001) but less light physical activity (t = ?3.17, P = .002) and sedentary behaviour (t = ?3.91, P < .001) in physical education than in exergaming. Overall, physical education was more effective in generating MVPA than other segments over the school day. The after-school segment holds potential as an avenue for promoting children’s MVPA, as this long period could be better utilised to organise structured physical activity.  相似文献   

12.
Little is known about the influence of different types and sources of social support on physical activity in adolescents. The aim of this study was to analyse the association between physical activity and different types and sources of social support in adolescents. The sample consisted of 2,859 adolescents between 14–19 years of age in the city of João Pessoa, in Northeastern Brazil. Physical activity was measured with a questionnaire and social support from parents and friends using a 10-item scale five for each group (type of support: encouragement, joint participation, watching, inviting, positive comments and transportation). Multivariable analysis showed that the types of support provided by parents associated with physical activity in adolescents were encouragement for females (P < 0.001) and adolescents between 14–16 years of age (P = 0.003), and transportation (P = 0.014) and comments (P = 0.037) for males. The types of social support provided by friends were: joint participation in male adolescents (P < 0.001) and in these 17–19-year-olds (P < 0.001), and comments in both genders (males: P = 0.009; females: P < 0.001) and 14–16-year-olds (P < 0.001). We conclude that the type of social support associated with physical activity varies according to its source, as well as the gender and age of the adolescents.  相似文献   

13.
Abstract

The aims of the present study were (1) to analyse the physical demands of top-class referees and (2) to compare their official FIFA fitness test results with physical performance during a match. The work rate profiles of 11 international referees were assessed during 12 competitive matches at the 2003 FIFA Under-17 World Cup and then analysed using a bi-dimensional photogrammetric video analysis system based on direct lineal transformation (DLT) algorithms. In the first 15 min of matches, the referees were more active, performing more high-intensity exercise (P < 0.01) than in the first 15 min of the second half. During the second half of matches, the referees covered a shorter distance (P < 0.01), spent more time standing still (P < 0.05), and covered less ground cruising (P < 0.05), sprinting (P < 0.05), and moving backwards (P < 0.001) than in the first half. Also in the second 45 min, the distance of referees from infringements increased (P < 0.05) in the left attacking zone of the filed. There was also a decrease (P < 0.05) in performance in the period following the most high-intensity activity, compared with the mean for the 90 min. Time spent performing high-intensity activities during a match was not related to performance in the 12-min run (r 2 = 0.30; P < 0.05), the 200-m sprint (r 2 = 0.05; P < 0.05), or the 50-m sprint (r 2 = 0.001; P < 0.05). The results of this study show that: (1) top-class referees experienced fatigue at different stages of the match, and (2) the typical field tests used by FIFA (two 50-m and 200-m sprints, followed by a 12-min run) are not correlated with match activities.  相似文献   

14.
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15.
Socio-economic status during childhood has been shown to be a strong predictor of adult health outcome. Therefore, we examined associations of parental educational level, household income and migrant background with physical fitness, spinal flexibility, spinal posture as well as retinal vessel diameters in children of an urban Swiss region. A total of 358 first graders of the Swiss canton Basel-Stadt (age: 7.3, SD: 0.4) were examined. Physical fitness (20 m shuttle run test, 20 m sprint, jumping sidewards and balancing backwards), spinal flexibility and spinal posture (MediMouse®, Idiag, Fehraltdorf, Switzerland) and retinal microcirculation (Static Retinal Vessel Analyzer, Imedos Systems UG, Jena, Germany) were assessed. Parental education, household income, migrant background and activity behaviour were evaluated with a questionnaire. Parental education was associated with child aerobic fitness (P = 0.03) and screen time (P < 0.001). Household income was associated with jumping sidewards (P = 0.009), balancing backwards (P = 0.03) and sports club participation (P = 0.02). Migrant background was associated with BMI (P = 0.001), body fat (P = 0.03), aerobic fitness (P = 0.007), time spent playing outdoors (P < 0.001) and screen time (P < 0.001). For spinal flexibility and retinal vessel diameter, no associations were found (0.06 < P < 0.8). Low parental education, low household income and a migrant background are associated with poor physical fitness, higher BMI and body fat percentage and low-activity behaviour.  相似文献   

16.
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   

17.
Abstract

The purpose of this study was to evaluate the impact of an extra-curricular school sport programme to promote physical activity among adolescents. One hundred and sixteen students (mean age 14.2 years, s = 0.5) were assigned to an intervention (n = 50) or comparison group (n = 66). The 8-week intervention involved structured exercise activities and information sessions. Four days of pedometer monitoring and time spent in non-organized physical activity and sedentary behaviours were measured at baseline and post-test. At baseline, participants were classified using steps per day as low-active (girls <11,000, boys <13,000) or active (girls ≥ 11,000, boys ≥ 13,000) and the effects of the intervention were assessed using these subgroups. Adolescents in the intervention group classified as low-active at baseline increased their step counts across the 8-week intervention (baseline: 7716 steps/day, s = 1751; post-test: 10,301 steps/day, s = 4410; P < 0.05) and accumulated significantly more steps (P < 0.05) than their peers in the comparison group (baseline: 8414 steps/day, s = 2460; post-test: 8248 steps/day, s = 3674; P = 0.879). The results of the present study provide further evidence that physical activity monitoring using pedometers is an effective strategy for increasing activity among low-active adolescents.  相似文献   

18.
This study investigated the effects of epoch length and cut point selection on adolescent physical activity intensity quantification using vertical axis and vector magnitude (VM) measurement with the ActiGraph GT3X+ accelerometer. Four hundred and nine adolescents (211 males; 198 females) aged 12–16 years of age wore accelerometers during waking hours. The GT3X+ acceleration counts were reintegrated into 1, 5, 15, 30 and 60 s epoch lengths for both vertical axis and VM counts. One cut point was applied to vertical axis counts and three different cut points were applied to VM counts for each epoch length. Significant differences (P < 0.01) in mean total counts per day were observed between vertical axis and VM counts, and between epoch lengths for VM only. Differences in physical activity levels were observed between vertical and VM cut points, and between epoch lengths across all activity intensities. Our findings illustrate the magnitude of differences in physical activity outcomes that occur between axis measurement, cut points and epoch length. The magnitude of difference across epoch length must be considered in the interpretation of accelerometer data and seen as a confounding variable when comparing physical activity levels between studies.  相似文献   

19.
Abstract

In a field setting, we compared a physical activity questionnaire (SQUASH), a 24-hour recall measure (Physical Activity Scale; PAS), and an accelerometer to: (1) quantify the amount of time spent in light, moderate, and vigorous physical activity; (2) calculate activity scores; and (3) categorize participants by physical activity tertiles. For 7 consecutive days, 103 participants (61% males, 39% females; mean age 36.8 years, mean body mass index 26.6 kg·m?2) wore an accelerometer and completed the PAS. Immediately before these 7 days, the participants completed the SQUASH and underwent anthropometric measurements (weight and height). Time spent in light (<3 METs), moderate (3–6 METs), and vigorous (≥6 METs) activity was calculated. Significant correlations were observed between the PAS and accelerometer in the population as a whole (r=0.66, P<0.001), the males (r=0.76, P<0.001), participants of normal weight (r=0.62, P<0.05), and those who were overweight (r=0.53, P<0.01). Correlations between the SQUASH and accelerometer were only significant for males (r=0.62, P<0.05) and overweight individuals (r=0.40, P<0.05). Moderate agreement was observed between tertiles for the accelerometer and PAS activity scores in the overall population (weighted kappa =0.47; 95% confidence interval =0.27–0.67) but not between the accelerometer and SQUASH. In conclusion, a 7-day administration of the PAS is a useful measure for classification of physical activity in the population studied. The SQUASH has practical advantages in terms of convenience of administration, but its usefulness in estimating physical activity is limited.  相似文献   

20.
Wrist-based accelerometers are increasingly used to assess physical activity (PA) in population-based studies; however, cut-points to translate wrist-based accelerometer counts into PA intensity categories are still needed. The purpose of this study was to determine wrist-based cut-points for moderate- and vigorous-intensity ambulatory PA in adults for the Actical accelerometer. Healthy adults (n = 24) completed a four-phase treadmill exercise protocol (1.9, 3.0, 4.0 and 5.2 mph) while wearing an Actical accelerometer on their wrist. Metabolic equivalent of task (MET) levels were assessed by indirect calorimetry. Receiver operating characteristics (ROC) curves were generated to determine accelerometer counts that maximised sensitivity and specificity for classification of moderate (≥3 METs) and vigorous (>6 METs) ambulatory activity. The area under the ROC curves to discriminate moderate- and vigorous-intensity ambulatory activity were 0.93 (95% confidence interval [CI]: 0.90–0.97; P < 0.001) and 0.96 (95% CI: 0.94–0.99; P < 0.001), respectively. The identified cut-point for moderate-intensity ambulatory activity was 1031 counts per minute, which had a corresponding sensitivity and specificity of 85.6% and 87.5%, respectively. The identified cut-point for vigorous intensity ambulatory activity was 3589 counts per minute, which had a corresponding sensitivity and specificity of 88.0% and 98.7%, respectively. This study established intensity-specific cut-points for wrist-based wear of the Actical accelerometer which are recommended for quantification of moderate- and vigorous-intensity ambulatory activity.  相似文献   

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