MVPA Time Research Articles

A comparison of children's diet and movement behaviour patterns derived from three unsupervised multivariate methods.

BackgroundBehavioural patterns are typically derived using unsupervised multivariate methods such as principal component analysis (PCA), latent profile analysis (LPA) and cluster analysis (CA). Comparability and congruence between the patterns derived from these methods has not been previously investigated, thus it’s unclear whether patterns from studies using different methods are directly comparable. This study aimed to compare behavioural patterns derived across diet, physical activity, sedentary behaviour and sleep domains, using PCA, LPA and CA in a single dataset.MethodsParent-report and accelerometry data from the second wave (2011/12; child age 6-8y, n = 432) of the HAPPY cohort study (Melbourne, Australia) were used to derive behavioural patterns using PCA, LPA and CA. Standardized variables assessing diet (intake of fruit, vegetable, sweet, and savoury discretionary items), physical activity (moderate- to vigorous-intensity physical activity [MVPA] from accelerometry, organised sport duration and outdoor playtime from parent report), sedentary behaviour (sedentary time from accelerometry, screen time, videogames and quiet playtime from parent report) and sleep (daily sleep duration) were included in the analyses. For each method, commonly used criteria for pattern retention were applied.ResultsPCA produced four patterns whereas LPA and CA each generated three patterns. Despite the number and characterisation of the behavioural patterns derived being non-identical, each method identified a healthy, unhealthy and a mixed pattern. Three common underlying themes emerged across the methods for each type of pattern: (i) High fruit and vegetable intake and high outdoor play (“healthy”); (ii) poor diet (either low fruit and vegetable intake or high discretionary food intake) and high sedentary behaviour (“unhealthy”); and (iii) high MVPA, poor diet (as defined above) and low sedentary time (“mixed”).ConclusionWithin this sample, despite differences in the number of patterns derived by each method, a good degree of concordance across pattern characteristics was seen between the methods. Differences between patterns could be attributable to the underpinning statistical technique of each method. Therefore, acknowledging the differences between the methods and ensuring thorough documentation of the pattern derivation analyses is essential to inform comparison of patterns derived through a range of approaches across studies.

Association of daily composition of physical activity and sedentary behaviour with incidence of cardiovascular disease in older adults

BackgroundModerate-to-vigorous physical activity (MVPA) is proposed as key for cardiovascular diseases (CVD) prevention. At older ages, the role of sedentary behaviour (SB) and light intensity physical activity (LIPA) remains unclear. Evidence so far is based on studies examining movement behaviours as independent entities ignoring their co-dependency. This study examines the association between daily composition of objectively-assessed movement behaviours (MVPA, LIPA, SB) and incident CVD in older adults.MethodsWhitehall II accelerometer sub-study participants free of CVD at baseline (N = 3319, 26.7% women, mean age = 68.9 years in 2012–2013) wore a wrist-accelerometer from which times in SB, LIPA, and MVPA during waking period were extracted over 7 days. Compositional Cox regression was used to estimate the hazard ratio (HR) for incident CVD for daily compositions of movement behaviours characterized by 10 (20 or 30) minutes greater duration in one movement behaviour accompanied by decrease in another behaviour, while keeping the third behaviour constant, compared to reference composition. Analyses were adjusted for sociodemographic, lifestyle, cardiometabolic risk factors and multimorbidity index.ResultsOf the 3319 participants, 299 had an incident CVD over a mean (SD) follow-up of 6.2 (1.3) years. Compared to daily movement behaviour composition with MVPA at recommended 21 min per day (150 min/week), composition with additional 10 min of MVPA and 10 min less SB was associated with smaller risk reduction – 8% (HR, 0.92; 95% CI, 0.87–0.99) – than the 14% increase in risk associated with a composition of similarly reduced time in MVPA and more time in SB (HR, 1.14; 95% CI, 1.02–1.27). For a given MVPA duration, the CVD risk did not differ as a function of LIPA and SB durations.ConclusionsAmong older adults, an increase in MVPA duration at the expense of time in either SB or LIPA was found associated with lower incidence of CVD. This study lends support to public health guidelines encouraging increase in MVPA or at least maintain MVPA at current duration.

Isotonic quadriceps endurance is better associated with daily physical activity than quadriceps strength and power in COPD: an international multicentre cross-sectional trial

Knowledge about modifiable determinants of daily physical activity (PA) in patients with chronic obstructive pulmonary disease (COPD) is crucial to design effective PA interventions. The present study aimed to determine the contribution of quadriceps strength, power and endurance to daily PA in COPD. Additionally, for quadriceps endurance, we also aimed to determine to what extent the association varies according to the mode of movement (isotonic, isometric, or isokinetic). Using a multicentre cross-sectional trial design we determined the contribution of quadriceps function to daily PA (steps, sedentary time and time spent doing moderate-to-very-vigorous physical activity [MVPA]) using bivariate and partial Pearson correlation analysis (r) and multiple linear regression models (ΔR2). Pre-determined controlling factors were sex, age, body mass index (BMI), COPD-assessment test, forced expiratory volume in one second in percent of the predicted value (FEV1pred), and distance walked on the 6-minute walk test. Eighty-one patients with COPD (mean ± SD: age 67 ± 8 years, FEV1pred 57 ± 19%, daily steps 4968 ± 3319, daily sedentary time 1016 ± 305 min, and MVPA time 83 ± 45 min) were included. Small to moderate bivariate correlations (r = .225 to .452, p < .05) were found between quadriceps function and measures of PA. The best multiple linear regression models explained 38–49% of the variance in the data. Isotonic endurance was the only muscle contributor that improved all PA models; daily steps (ΔR2 = .04 [relative improvement 13%] p = .026), daily sedentary time (ΔR2 = .07 [23%], p = .005) and MVPA-minutes (ΔR2 = .08 [20%], p = .001). Isotonic endurance was also independently associated with most PA variables, even when controlling for strength, power or isometric-isokinetic endurance properties of the muscle (r = .246 to .384, p < .05). In contrast, neither strength, power, isometric-or isokinetic endurance properties of the muscle was independently associated with PA measures when controlling for isotonic endurance (r = .037 to .219, p > .05). To conclude, strength, power, and endurance properties of the quadriceps were low to moderately associated with PA in patients with COPD. Isotonic quadriceps endurance was the only quadriceps property that was independently associated with the different measures of PA after controlling for a basic set of known determinants of PA, quadriceps strength or power, or isometric or isokinetic quadriceps endurance. Future longitudinal studies should investigate its potential as a modifiable determinant of PA.

Validity of the international physical activity questionnaire and bouchard diary in Chinese adults

Based on the accelerometer, the validity of the international physical activity questionnaire long version(IPAQ-L) and Bouchard diary were evaluated to measure the daily physical activity of Chinese adults aged 18-59 years old. A total of 200 Chinese adults were recruited in Yinzhou District of Ningbo City in 2019, including 78 males and 122 females, the three age groups 18-29, 30-49, 50 and above accounted for 19. 5%, 61. 5% and 18. 0%, respectively. The volunteers wore Actigraph WGT3 x-BT three-dimensional accelerometer for 3 days, and completed the 3 consecutive days& apos; Bouchard diary and the IPAQ-L. The physical activity energy expenditure(PAEE), sedentary inactivity time, light physical activity time(LPA) and moderate-to-vigorous physical activity time(MVPA) measured by the three tools were estimated respectively. Spearman analysis was used to analyze the correlation, the Friedman test and the Bland-Altman plot were used to test the homogeneity of the three method. 196 volunteers were included in this study. The correlation coefficients of PAEE between IPAQ and diary and accelerometer were 0. 32 and 0. 58, respectively, the correlation coefficients of sedentary behavior were 0. 17, 0. 25, and LPA time was 0. 33, and the estimated IPAQ for MVPA time better than diary. The difference test result showed that, except for IPAQ in the measurement of MVPA, there was no statistical difference from the accelerometer measurement result(P=0. 684), and the difference between other estimated values and the accelerometer measurement result was statistically significant(P& lt; 0. 01), Bland-Altman plot result showed that the diary and IPAQ had good consistency in the measurement of PAEE and IPAQ in the estimation of MVPA time, but there was an overestimation in PAEE. In addition, IPAQ had poor validity in measuring sedentary behavior and LPA. IPAQ and Bouchard diary have better validity in evaluating PAEE, and the diary is better than IPAQ. IPAQ has better validity in evaluating MVPA time, but has poor validity in estimating sedentary behavior and LPA time.

Levels of physical activity in children and adolescents with asthma: A systematic review and meta-analysis.

In children and adolescents with asthma, the disease may reduce the perceived capability to participate in physical activity (PA) contributing to an increase in the sedentary lifestyle. The literature is unclear as to whether children and adolescents with asthma differ their PA levels from their healthy peers. Our objective was to describe the different methods and instruments used to measure PA and to compare the PA levels of children and adolescents with asthma with those of their healthy peers. We conducted a systematic review of five databases. We included studies that compared the PA measured by objective and subjective instruments in children and adolescents with asthma versus controls. Two independent reviewers analyzed the studies, extracted the data, and assessed the quality of evidence. Of the 5966 reports returned by the initial search, 28 articles reporting on 3184 patients were included in the data synthesis. A forest plot showed that both groups had similar values of moderate to vigorous PA (MVPA; mean difference, -0.05 h/day; 95% confidence interval [CI], -0.11-0.01; p = .13), sedentary time (mean difference 0.00 h/day; 95% CI, -0.22-0.23 h/day; p = .99) and steps/day (mean difference 354 steps/day; 95% CI, -563-1270 steps/day; p = .45). Children and adolescents with asthma have similar MVPA, steps/day, and sedentary time compared to the controls. The main instruments used were questionnaires and accelerometers.

Promoting More Physical Activity and Less Sedentary Behaviour During the COVID-19 Situation – SportStudisMoveYou (SSMY): A Randomized Controlled Trial

<strong>Objective:</strong> To determine the effect of an innovative, online-based intervention, addressing the possible decline of physical activity (PA) and increase of sedentary behavior (SB) during COVID-19 stay at home restrictions in Switzerland. <strong>Methods:</strong> This study investigated the effect of a two-week, social cognitive theory based, online-video moderate to vigorous (MV)PA or SB intervention on MVPA and SB behaviour and intention via a 3 group by 2 time point parallel randomized controlled trial during the COVID-19 pandemic. Adults (≥18 yo) were recruited over the internet between April 10th and April 19th 2020 (n = 129; 75.2% female; mean age = 29.0 [SD 11.8] years). Both intervention groups received five videos targeting either SB for the SB group or MVPA for the MVPA group and were compared to an attention control group (fruit and vegetable consumption). It was hypothesized that MVPA time and intention would increase for the MVPA group and the SB group would outperform control on SB behaviour and intention indicators. <strong>Results:</strong> No significant interactions were found for the MVPA group (n = 41) versus control (n = 40). Only one significant interaction was measured for the SB group (n = 48; intention of active breaks F = (2,114) = 5.84, p = 0.004, η_p² = 0.09). Although mostly non-significant and small effects, the MVPA group showed results pointing in the hypothesized direction on all PA indicators and the SB on all SB indicators, respectively. <strong>Conclusion:</strong> Considering this study’s limitations (e.g. small intervention dose), video-based online PA and SB interventions seem promising and feasible. This approach is appropriate for COVID-19 and other stay at home situations.

Are physical activity and sedentary behavior patterns contributing to diabetes and metabolic syndrome simultaneously?

To investigate cross-sectional association between sedentary activities and moderate-to-vigorous physical activities’ (MVPA) patterns, and the likelihood of having diabetes, MetS, or both conditions. This cross-sectional analysis from the National Health and Nutrition Examination Survey 2003-2004 and 2005-2006 cycles included 2456 adults. The primary exposure variables were sedentary and MVPA patterns (1-, 5-, 10-, 30-, and 60-minute bouts) measured by accelerometer. The primary outcome measure was the subgroup categorization: healthy group, MetS group, diabetes group, and Mets & diabetes group. No differences were observed regarding proportion of sedentary patterns among groups, but differences were observed for the proportion of time spent doing MVPA in 5-, 10-, and 30-minute bouts among groups (all P < .05). When comparing individuals having both MetS & diabetes to the MetS group and the diabetes group, all bout lengths of sedentary behavior were significantly different (P < .05). The patterns of sedentary behavior were not associated with higher odds of being classified with Mets & diabetes when adjusted for total MVPA time (all P > .05). Interestingly, the odds of being in the healthy group were associated with MVPA patterns following adjustment for total sedentary time. The findings suggest it is more important to focus on exercise performed at moderate-to-vigorous intensity, of any bout length, compared to sitting less to lower the odds of MetS and diabetes.

Global Accelerometer-Derived Physical Activity Levels from Preschoolers to Adolescents: A Systematic Review, Subgroup Analysis, and Meta-Analysis

Purpose: The purpose of the study was to examine global accelerometer-measured daily MVPA changes from preschool age to adolescence as well as gender differences in MVPA while controlling for the continents and cut points. Methods: A comprehensive electronic search was conducted through August 2020 that includes 30 databases such as Academic Search Ultimate, Child Development & Adolescent Studies, Education Full Text, ERIC, General Science, PsycINFO, ScienceDirect, and SPORTDiscuss (PROSPERO registration No CRD42020172495). We included either cross-sectional or longitudinal MVPA tracking studies with daily MVPA being measured by waist-worn accelerometers and determined by either Freedson 3 METs, 4 METs, or Everson cut points for preschoolers, children, and adolescents. Systematic review with meta-analysis was used. Results: Researchers analyzed 124 studies with a total of 57,587 participants were analyzed. The combined data showed significant MVPA differences among various continents (p < .001) or cut points (p < .05 to .001) for both preschoolers, children, and adolescence. Globally, when continents and cut points were controlled, individuals’ daily MVPA time decreased every year by 6.88, 8.02, and 6.01 minutes from preschool age to adolescence, preschool age to children, and children to adolescence, respectively. When cut points and continents were controlled, boys had significantly higher daily MVPA than girls for all three age groups (p < .05 to p < .0001). Conclusions: Globally, individuals’ daily MVPA time tends to decrease dramatically each year from preschool age to adolescence. The decline is faster from preschool age to children. Systematic Review Registration Number: CRD42020172495 Funding Statement: The authors received no financial support for the research, authorship, and/or publication of this article. Declaration of Interests: The authors declare no competing interests.

Physical activity, sedentary behavior and educational outcomes in university students: A systematic review

Objective To systematically review available evidence focusing on the relationship between physical activity (PA), sedentary behavior (SB), and educational outcomes (EO), among university students. Method: Articles published in English and up to April 2019 were eligible to be included in the review if they examined associations between either PA or SB measures and EO in undergraduate university students. Results: Thirty-five articles met the eligibility criteria. The majority of papers used self-report measures of PA and SB and were rated as demonstrating poor quality (22/35). Evidence indicated no associations with EO for overall PA, MPA, VPA, and indeterminate associations for MVPA and leisure-based screen time. Conclusion: Mixed findings for PA, SB, and EO were found. Future studies should use more rigorous designs, including robust measures of relevant outcomes, to further our understanding of this area.

Associations of sitting and physical activity with grip strength and balance in mid-life: 1970 British Cohort Study.

Strength and balance training are now recommended in many physical activity (PA) guidelines. However, it is unclear whether these recommendations are applicable to middle‐aged adults. We aimed to examine the associations of sitting and physical activity times with grip strength and standing balance performance in mid‐life. Up to 4726 participants from the 1970 British Cohort study, with data on sitting and activity (measured using a thigh‐worn accelerometer (activPAL3‐micro)), grip strength and balance times at age 46 years were included in analyses. Associations of sitting, moderate‐vigorous, and total PA times with grip strength and balance performance were tested using linear and multinomial logistic regression models, respectively. Greater time spent sitting was associated with weaker grip strength even after adjustment for potential confounders and MVPA time (fully adjusted regression coefficient: −0.51 kg (95% CI: −0.63, −0.39) per 1‐hour sitting/day). Associations of PA time with grip strength were not independent of sitting time. There was only a weak association between sitting time and balance performance but greater MVPA and total PA times were associated with higher relative risks of successfully balancing for 30 seconds with eyes closed (vs poor balance). However, these associations were fully attenuated after adjustments for covariates. In summary, among a sample of middle‐aged adults a robust association between sitting time and grip strength was observed. These findings suggest potential benefits of actively promoting less sitting alongside activities that specifically benefit muscle strength and balance performance in mid‐life to ensure that people maintain all important aspects of their physical capability as they age.

The physical activity paradox revisited: a prospective study on compositional accelerometer data and long-term sickness absence

BackgroundThe ‘physical activity paradox’ advocates that leisure physical activity (PA) promotes health while high occupational PA impairs health. However, this paradox can be explained by methodological limitations of the previous studies—self-reported PA measures, insufficient adjustment for socioeconomic confounding or not addressing the compositional nature of PA. Therefore, this study investigated if we still observe the PA paradox in relation to long-term sick absence (LTSA) after adjusting for the abovementioned limitations.MethodsTime spent on moderate-to-vigorous physical activity (MVPA) and remaining physical behaviors (sedentary behavior, standing, light PA and time in bed) at work and in leisure was measured for 929 workers using thigh accelerometry and expressed as isometric log-ratios (ilrs). LTSA was register-based first event of ≥6 consecutive weeks of sickness absence during 4-year follow-up. The association between ilrs and LTSA was analyzed using a Cox proportional hazards model adjusted for remaining physical behaviors and potential confounders, then separately adjusting for and stratifying by education and type of work.ResultsDuring the follow-up, 21% of the workers experienced LTSA. In leisure, more relative MVPA time was negatively associated with LTSA (20% lower risk with 20 min more MVPA, p = 0.02). At work, more relative MVPA time was positively associated with LTSA (15% higher risk with 20 min more MVPA, p = 0.02). Results remained unchanged when further adjusted for or stratified by education and type of work.ConclusionThese findings provide further support to the ‘PA paradox’.

Effects of a 12-Week Multifaceted Wearable-Based Program for People With Knee Osteoarthritis: Randomized Controlled Trial.

BackgroundCurrent guidelines emphasize an active lifestyle in the management of knee osteoarthritis (OA), but up to 90% of patients with OA are inactive. In a previous study, we demonstrated that an 8-week physiotherapist (PT)-led counseling intervention, with the use of a Fitbit, improved step count and quality of life in patients with knee OA, compared with a control.ObjectiveThis study aimed to examine the effect of a 12-week, multifaceted wearable-based program on physical activity and patient outcomes in patients with knee OA.MethodsThis was a randomized controlled trial with a delay-control design. The immediate group (IG) received group education, a Fitbit, access to FitViz (a Fitbit-compatible app), and 4 biweekly phone calls from a PT over 8 weeks. Participants then continued using Fitbit and FitViz independently up to week 12. The delay group (DG) received a monthly electronic newsletter in weeks 1 to 12 and started the same intervention in week 14. Participants were assessed in weeks 13, 26, and 39. The primary outcome was time spent in daily moderate-to-vigorous physical activity (MVPA; in bouts ≥10 min) measured with a SenseWear Mini. Secondary outcomes included daily steps, time spent in purposeful activity and sedentary behavior, Knee Injury and OA Outcome Score, Patient Health Questionnaire-9, Partners in Health Scale, Theory of Planned Behavior Questionnaire, and Self-Reported Habit Index.ResultsWe enrolled 51 participants (IG: n=26 and DG: n=25). Compared with the IG, the DG accumulated significantly more MVPA time at baseline. The adjusted mean difference in MVPA was 13.1 min per day (95% CI 1.6 to 24.5). A significant effect was also found in the adjusted mean difference in perceived sitting habit at work (0.7; 95% CI 0.2 to 1.2) and during leisure activities (0.7; 95% CI 0.2 to 1.2). No significant effect was found in the remaining secondary outcomes.ConclusionsA 12-week multifaceted program with the use of a wearable device, an app, and PT counseling improved physical activity in people with knee OA.Trial RegistrationClinicalTrials.gov NCT02585323; https://clinicaltrials.gov/ct2/show/NCT02585323

Algorithms, Filters And Corrections Compound Differences Between Multiple Lifestyle Physical Activity Estimates

Physical activity (PA) can be objectively and conveniently measured using accelerometers. The use of wrist-worn devices has grown dramatically over the past decade, becoming the preferred choice in many recreational, clinical and research applications. ActiGraph is a leading company in this field, wherein data from accelerometers can be analyzed in their ActiLife software. However, the effects of multiple algorithms, filters and corrections on PA outcomes are not always clear. PURPOSE: To examine how lifestyle PA estimates are impacted by multiple scoring methods in a commercial software platform. METHODS: We collected lifestyle wrist-worn accelerometer data (ActiGraph GT3X+) from 132 adults with a range of activity levels with and without chronic pain (low back pain, fibromyalgia, pain-free). We analyzed accelerations in ActiLife using multiple algorithms, with and without the wrist correction and proprietary low-frequency extension (LFE) across four PA domains: total EE (METs), active EE (kCal), MVPA time, and steps. Accelerometer and self-reported (International Physical Activity Questionnaire) PA outcomes were compared. RESULTS: PA estimates differed notably across most algorithms with highly variable, but typically large effect sizes (p < 0.05, median % change = 33.5% [6.9% – 62.6%], d = 1.04 [0.60 – 1.45]). The wrist correction reduced PA estimates across all outcomes (p < 0.05, % change = -15.0% [-3.9% – -31.8%], d = 0.56 [0.31 – 0.93]) save steps and one daily EE algorithm (no change). The LFE increased steps considerably (p < 0.05, % change = 72.3%, d = 1.44) yet had little effect across all other outcomes (p < 0.05, % change = 4.7% [2.9% – 4.9%], d = 0.13 [0.11 – 0.14]). Differences were always greater when multiple factors were considered (% change = 89.2% [80.7% – 201.3%]). Correlations between objective and self-reported PA were typically moderate (ρ = 0.55 [0.36 – 0.88]), were further reduced by the wrist correction, and affected minimally by the LFE. CONCLUSIONS: Previously-validated scoring methods are not necessarily interchangeable. The wrist correction and LFE inconsistently inflate PA estimates, with variability increasing when multiple factors are considered. Researchers should consistently report detailed methodology to optimize comparisons across studies and to normative guidelines.

Association of BMI category with change in children\u2019s physical activity between ages 6 and 11 years: a longitudinal study

Background/objectivesTo examine the association of body mass index (BMI) with change in children’s physical activity and sedentary time between ages 6 and 11.ParticipantsA total of 2132 children participated from 57 schools in Southwest England, from the B-PROACT1V study.MethodsMean minutes of MVPA and sedentary time per day were derived from accelerometer-based measurements at ages 6, 9 and 11. Linear multilevel models examined the association of BMI categories with MVPA and sedentary time between 6 and 11, adjusting for seasonality, wear time, gender and household education. Differences in change over time were examined using interaction terms.ResultsAverage weekday MVPA decreased between ages 6 and 11 by 2.2 min/day/year (95% CI: 1.9 to 2.5), with a steeper decline at weekends. Average sedentary time increased at a rate of 12.9 min/day/year (95% CI: 12.2 to 13.6). There were no differences in mean levels of MVPA by BMI categories at age 6, but differences emerged as children aged, with the gap between children who were healthy weight and overweight increasing by 1.7 min/day (95% CI: 0.8–2.6) every year, and between healthy and obese by 2.0 min/day (95% CI: 0.9–3.1) each year. Children who were overweight/obese engaged in less average weekday sedentary time at age 6 than those of healthy weight, but the gap closed by age 11.ConclusionMVPA declines and sedentary time increases on average for all children between ages 6 and 11. While there are no differences in activity levels by BMI category at age 6, differences in MVPA emerge over time for those who are overweight and obese. Developing interventions that support children to retain activity levels as they approach older childhood, particularly those who are overweight/obese could improve public health.

Objectively measured physical activity and psychosocial functioning in young children: The GECKO Drenthe cohort

ABSTRACTThe global trend in inactivity in children may be related to psychosocial problems. We investigated the cross-sectional association between physical activity (PA) levels and psychosocial functioning in 3.4–7.3-year-old children. Children from the Dutch GECKO birth cohort (N = 898; 51.6% boys) had PA levels assessed objectively by accelerometry (ActiGraph GT3X) for at least three days. Linear regression analysis was used for associations with psychosocial functioning (parent report of the Strengths and Difficulties Questionnaire), controlling for gender, age and socio-economic status. Higher total and moderate-to-vigorous PA levels (MVPA) were associated with higher Total Difficulty scores, and sedentary time to lower Total Difficulty scores. More time spent in MVPA was significantly associated to “hyperactivity/inattention” in both boys (Standardized BBOYS = 0.192) and girls (Std.BGIRLS = 0.139) whereas for the time in sedentary behaviour, a reverse association was found only in boys (Std.BBOYS = −0.230). In boys only, more time in MVPA (Std.BBOYS = 0.154) and less time in sedentary behaviour (Std.BBOYS = −0.147), were significant determinants for ‘behavioural problems’. When using objectively measured PA, parents report more hyperactivity/inattention and behavioural problems in the more active children, and less in the more sedentary children, most clearly for boys. High levels of PA might be an indicator of psychosocial problems in young children.

Cross-sectional Correlates of Physical Activity and Sedentary Time among Young Adult Cancer Survivors

Cancer survivors are less active than the general population. Previous research has examined predictors of physical activity among cancer survivors; however, few studies have focused on adolescent and young adult (AYA) survivors. PURPOSE: To examine cross-sectional relationships between demographic, psychosocial, disease-related characteristics, and measures of physical activity (steps, MVPA, and sedentary time) among AYA cancer survivors. METHODS: Eligible participants were diagnosed with cancer between 18-39y, >6 months post-treatment, and engaged in <60 min/wk of exercise. Participants wore an activPAL monitor for 7-days to obtain estimates of physical activity and sedentary time. Participants self-reported their health history (e.g., cancer type and treatment), demographics, psychosocial correlates (e.g., self-efficacy), and symptoms (e.g., fatigue). We used pearson correlations to assess bivariate relationships. For variables with significant correlations, we used linear regression models to assess the relationship between activity variables, demographics, and psychosocial factors. RESULTS: Fifty-four participants were eligible and provided informed consent; of those, 51 completed the baseline assessments and 48 had valid baseline data. Fatigue was significantly correlated with steps per day (R = -0.39), minutes of MVPA (R = -0.38), and percent of time sedentary (R = 0.40). There were no other significant correlations between psychosocial variables and steps, MVPA, or sedentary time. After adjusting for age and gender, breast cancer survivors had significantly higher steps per day than other cancer types (1,651 steps), more minutes of MVPA (13.7 min/day) and less sedentary time (-8.4%, p<0.05). The relationship between higher levels of fatigue, less physical activity, and more sedentary time remained significant after adjusting for age, gender, and cancer type (p<0.05). CONCLUSIONS: Preliminary results indicate a significant relationship between higher levels of fatigue, more sitting time, and less daily physical activity. Future research is needed to determine if increasing physical activity will reduce fatigue in AYA cancer survivors.Supported by Frost Fund and Cal Poly RSCA Grant.

Validity and Reliability of the Exercise Vital Sign Questionnaire in an Ethnically Diverse Group: A Pilot Study.

The purpose of this study was to determine the validity and reliability of the Exercise Vital Sign (EVS) questionnaire in an ethnically diverse sample. Participants (N = 39) were asked to wear an accelerometer at the hip for at least 7 days and to complete the EVS at the beginning (T1) and end (T2) of the wear period. The EVS questionnaire validity was determined against accelerometry, and bias was calculated as the mean difference between measures. The sensitivity and specificity of the EVS questionnaire were also evaluated. The reliability of the questionnaire was calculated using intraclass correlation coefficient (ICC) between EVS responses at T1 and T2. The mean difference in EVS- and accelerometer-determined time in MVPA was 24 min/wk. The reliability for the questionnaire was excellent (ICC = 0.98). The EVS specificity and sensitivity at T2 were 56% and 78%, respectively. The EVS questionnaire may be an acceptable measure of weekly MVPA time compared to accelerometry in an ethnically diverse sample; however, further research is needed to confirm these findings.

PO-018 A Follow-up Study of 8-10 age pupil's physical activity status and related factor

Objective Regular physical activity in children has many benefits，including reducing the occurrence of obesity and lower levels of cardiovascular disease risk factors, promote bone mass deposition, improve health. Our research in order to using accelerometer survey children daily PA status in our country, and analyzes its characteristic.&#x0D; Methods Our research assessed the PA of the same group of children in Beijing yuxin Primary school for three consecutive years using ActiGraph accelerometers. The total available valid data are 183 children (male 94, female 89).&#x0D; Results (1)The average total PA is 627.2±134.5 counts/min（boy accrued 665.6 ± 139.1 counts/min and girl 579.8 ± 112.2 counts/min ）, among them boy accrued 59.0min/d and girl 48.1min/d of MVPA. 35% of participants could meet the WHO PA guideline (boys =49%, girls = 18%).&#x0D; (2) MVPA increased significantly from 8 to 9 years of age（MVPA of 8year-old children:53.2min/d,9year-old children:56.1min/d）and MVPA decline slightly from 9 to 10 (10 year-old children:55.8min/d).And both boys and girls meet this regular.&#x0D; (3) Both in weekdays and weekend, the MVPA time of boys (60.2min/d,57.8min/d) are outstandingly higher than girls ( 49.7min/d ,46.5min/d).&#x0D; (4) TWO-way (gender *BMI category) ANOVA revealed that girls were less active than boys.&#x0D; (5) The moderate and vigorous physical activity time of obese children in weekends are 42.3 min/d while those of normal children are 49.7 min/d, (p&lt;0.05).&#x0D; (6) The total PA level, VPA, MVPA are negatively correlated with body fat percentage while LPA is positively correlated with BMI.&#x0D; Conclusions Objective data indicated that Chinese youth are generally not physically active enough, and lower levels of PA were observed in girls, and during weekend days. The findings of this study will better inform the development of PA-related policies in schools, the design of PA intervention programs.&#x0D;

PL - 024 The characteristics for the primary school students’ physical activity

Objective This thesis provides a theoretical basis for improving children’s physical activity levels and promoting the healthy development of primary school children.&#x0D; Methods Measuring the height, shape index of children which are in 3-5 grades of primary school in Nanjing and taking the BMI cut-off point of the Cole as the object of this study BMI evaluation criteria. Applying the ActiGraph GT3X accelerometer to measure the physical activity of children in seven consecutive days which includes five school days and two weekend days. By counting the physical activity in a 60s interval, children’s physical activity can be evaluated. Besides, using 100cm as the cut-off point, the number of students’ sedentary breaks can be calculated. And the relationship between the results and students’ BMI characteristics can be discussed.&#x0D; Results (1) For the male students, the average sedentary breaks, LPA and MVPA time is 849.47min, 297.01min and 37.99 min respectively. And for the female students, the sedentary breaks, LPA and MVPA time is 874.12min, 272.33min, and 32.55min respectively. The male students’ MVPA time is significant higher than the female students (P&lt;0.05), but for both of them, the MVPA time cannot achieve the international children’s physical activity daily recommended amount which is 60min. Besides, there is no difference between different grades(P&gt;0.05). (2) Students’ daily MVPA time was significantly higher than the weekend MVPA time (P &lt;0.05). Male students’ MVPA time in the school days is higher than the MVPA time in the weekend(P&lt;0.01). For the children in different body shape, the MVPA time in the school days is higher than that in the weekend(P&lt;0.05). In the school days, the male students’ MVPA time is significant higher than that of female. (P&lt;0.05). In the weekend, the normal group’s MVPA time is much higher than that of overweight and obese groups(P&lt;0.05).(3) The sedentary breaks of normal group is less than that of overweight and obese groups(P&lt;0.05). There is no significant difference between different gender, grades and BMI(P&gt;0.05).&#x0D; Conclusions （1）Male students’ MVPA time is higher than the female students.（2）The MVPA time in the school days is much higher than in the weekend. In terms of the sedentary breaks, there is no difference between different gender, grade and body shape.（3）Students with more sedentary breaks get lower BMI,and the change of LPA will be the primary cause of MVPA changing.

Variability in school children's activity occurs in the recess and before-school periods.

An accurate description of physical activity (PA) at school is required for appropriate health interventions. We examined PA patterns in children, and identified the time periods that influenced them. Forty students in five Japanese primary schools were asked to wear triaxial accelerometers for ≥7days. We obtained coefficients of variance (CV) at 15min intervals, and conducted factor analysis of the school periods. A questionnaire was used to investigate where students spent time before school, and during recess. The amount of PA, and its CV were higher around 8a.m. (before-school period), 10a.m. (morning recess), 1p.m. (lunch recess), and 4p.m. (commuting home from school). Moderate-vigorous PA (MVPA; ≥3.0 metabolic equivalent units [MET]) was highest during lunch recess and the after-school period (12.9 ± 7.4min and 12.6 ± 6.2min, respectively). The percentage of MVPA time was high (>15%) in the before-school period and morning and lunch recesses, but low (10%) in the after-school period. On factor analysis there were differences in PA patterns between the school period and the after-school period. The students who spent their time in the playground logged more MVPA time and less sedentary time (≤1.5 MET) than those who did not spend their time in the playground. Activities before school, and in the morning and lunch recesses influenced daily PA, and were different from after-school PA. Close attention to these periods may help in defining PA parameters during free time at school for PA interventions in children.