Light-intensity Physical Activity Time Research Articles

Physical activity in adults with and without rheumatoid arthritis: cross-sectional results from the Survey of Health, Ageing and Retirement in Europe (SHARE)

Objective Studies examining habitual physical activity levels and patterns in adults with rheumatoid arthritis (RA) using raw data from modern accelerometers are lacking. We aimed (i) to examine physical activity levels and patterns in adults with RA in their familiar environment, and (ii) to investigate whether physical activity levels differ throughout the day. Method Data were taken from Wave 8 of the Survey of Health, Ageing and Retirement in Europe, including N = 607 men and women who wore a triaxial accelerometer and had adequate information for RA and accelerometry data summarized as Euclidean norm minus one (ENMO, mg). Growth-curve models and simple contrast analysis were used to examine the effect of RA on daily patterns of physical activity levels, including mean total ENMO in mg, mean minutes of light-intensity physical activity (ENMO values ≥ 25 mg and ≤ 75 mg), and moderate-to-vigorous-intensity physical activity (ENMO values > 75 mg). Results Total physical activity averaged throughout the day was 25.0 and 28.6 mg for respondents with and without RA, respectively. Respondents with RA spent more time in light-intensity physical activity throughout the day (p < 0.001), but less time in moderate-to-vigorous-intensity physical activity between 4 am and 11 pm (p < 0.001) than respondents without RA. Conclusion Adults with RA were less physically active than adults without RA. However, there were no diurnal differences in physical activity.

Association of Malnutrition With Physical Activity Intensity in Patients With Subacute Stroke

ObjectiveTo investigate the relationship between nutritional status measured by the Global Leadership Initiative on Malnutrition (GLIM) criteria and the intensity of physical activity, and to determine the association between these factors and the activities of daily living (ADLs) in patients with subacute stroke during hospitalization. DesignA cross-sectional study. SettingThe study was conducted in the rehabilitation unit at a neurosurgical hospital. ParticipantsOne hundred and twenty-eight patients with subacute stroke (N=128). InterventionsNot applicable. Main Outcome MeasuresNutritional status was assessed using GLIM criteria. Sedentary behavior (SB), light-intensity physical activity (LIPA), and moderate-to-vigorous physical activity (MVPA) were measured using an accelerometer. Multiple regression analysis was used to investigate the relationship between nutritional status and intensity of physical activity. Moreover, the association of nutritional status and physical activity intensity with ADLs was determined using multiple regression analysis and mediation analysis. ResultsMalnutrition was associated with SB time (B = 16.241, P=.009) and LIPA time (B = -17.656, P=.002), but not MVPA time (B = -0.472, P=.776). SB time (B = -0.063, P=.009) and LIPA time (B = 0.093, P<.001) were associated with functional independence measure for motor function, while MVPA time (B = -0.080, P=.379) was not. SB time (coefficient = -10.785, P<.001) and LIPA time (coefficient = -12.054, P<.001) were significant mediators between nutrition status and ADLs. ConclusionsMalnutrition was associated with a SB time and LIPA time, but not MVPA time, in patients with sub-acute stroke. SB and LIPA times were associated with ADLs and mediated between nutrition status and ADLs in these patients. The association of nutritional status on physical activity and ADLs should be considered in stroke rehabilitation.

Daily patterns of physical activity, sedentary behavior, and prevalent and incident depression-The Maastricht Study.

This study aims to compare the accelerometer-measured daily patterns of PA and sedentary behavior among participants with and without prevalent/incident depressive symptoms. We used data from 5582 individuals in The Maastricht Study (59.9 ± 8.6 years, 50.3% women). Daily patterns of sedentary time, light-intensity physical activity (LiPA), moderate-to-vigorous physical activity (MVPA), and sit-to-stand transitions were objectively measured at baseline with the activPAL3 activity monitor. Depressive symptoms were assessed using the 9-item Patient Health Questionnaire, both at baseline and annually (median follow-up: 5.1 years). General linear models were used to compare patterns of physical activity and sedentary behavior between those with and without prevalent/incident depressive symptoms. Participants with prevalent depressive symptoms had significantly more sedentary time (18.6min/day) and lower LiPA (26.8min/day) and MVPA (4.8min/day) than participants without depressive symptoms. Considering the daily patterns, participants with prevalent depressive symptoms had significantly more sedentary time early in the afternoon (12:00-18:00), early evening (18:00-21:00), and during the night (00:00-03:00), less time in LiPA in all periods between 09:00-21.00 and less MVPA in the morning (09:00:12:00), early afternoon (12:00-15:00), and evening (18:00-21:00), than those without. Similar differences in activity and sedentary behavior patterns between those and without incident depressive symptoms were observed albeit the differences were smaller. Overall, we did not find specific time slots particularly associated with both prevalent and incident depressive symptoms. These findings may indicate that less sedentary time and more intense PA can be important targets for the prevention of depression irrespective of the timing of the day.

Differences in Accelerometer-Measured Physical Activity and Sedentary Behavior Between Middle-Aged Men and Women in Japan: A Compositional Data Analysis.

Differences in accelerometer-measured sedentary behavior and different physical activity (PA) intensities between men and women have been poorly described. The authors examined gender differences in time-use activity composition and total volume of PA. A cross-sectional mail survey was conducted from 2013 to 2015 with a randomized sample of 6000 middle-aged (40-64y) community-dwelling Japanese adults living in urban and regional cities. Participants wore Active style Pro HJA-350IT on their waist for 7 consecutive days. Gender differences in activity time use was examined using compositional data analysis to control for time spent in all activity measures. In total, 757 participants (303 men, 52.3 [7.1]y) with valid data were included in the analysis. Women spent on average 12.6% less time in sedentary behavior and 23.4% more time in light-intensity PA than men, whereas no significant difference was found for moderate to vigorous PA. Women accumulated a significantly greater volume of PA than men (17.8 vs 15.0 metabolic equivalent of task h/d). Japanese middle-aged women showed higher levels of PA than men because they spent more time in light-intensity PA. Given the health benefits of light-intensity PA, evaluating only moderate to vigorous PA may lead to an underestimation of women's participation in PA.

Higher levels of physical activity is associated with lower arterial stiffness in patients with resistant hypertension

Abstract Funding Acknowledgements Type of funding sources: Foundation. Main funding source(s): Portuguese Foundation for Science and Technology (FCT) European Regional Development Fund – Operational Competitiveness Factors Program (COMPETE) Background Physical activity has been associated with reduced arterial stiffness in patients with hypertension. However, in resistant hypertension, a specific population with an increased risk for target organ damage, cardiovascular morbidity, and mortality, the evidence is sparse. Purpose The present study aimed to determine the association between daily physical activity and arterial stiffness in patients with resistant hypertension. Methods Fifty-seven patients with resistant hypertension were recruited. Physical activity was objectively assessed during 7 consecutive days with accelerometers. Arterial stiffness was evaluated using carotid-femoral pulse wave velocity (cf-PWV) . Results Participants (50.9% men), aged 58.8 ± 9.4 years, were mainly overweight and were taking in average 4.5 antihypertensive medications. The cf-PWV showed an inverse correlation with light-intensity physical activity (r = -0.290, p = 0.029) and total daily physical activity (r = -0.287, p = 0.030). Additionally, cf-PWV tended to be inversely associated with the number of steps per day (r = -0.242, p = 0.069). Patients with higher risk of cardiovascular events (cf-PWV ≥ 10 m/s) tended to spend less time in light-intensity physical activity (324.0 ± 129.4 vs. 380.5 ± 103.1 min/day, p = 0.090) and to perform less total daily physical activity (351.5 ± 141.7 vs. 411.7 ± 109.1 min/day, p = 0.091) than participants with cf-PWV below the risk threshold value. Conclusions Higher levels of total physical activity and daily levels of light-intensity were associated to lower arterial stiffness. These results emphasize the importance of physical activity as a nonpharmacological tool for patients with resistant hypertension.

Physical activity profiles in Parkinson\u2019s disease

BackgroundIdentifying physical activity (PA) profiles of people with Parkinson’s Disease (PD) could provide clinically meaningful knowledge concerning how to tailor PA interventions. Our objectives were therefore to i) identify distinct PA profiles in people with PD based on accelerometer data, ii) explore differences between the profiles regarding personal characteristics and physical function.MethodsAccelerometer data from 301 participants (43% women, mean age: 71 years) was analysed using latent profile analyses of 15 derived PA variables. Physical function measurements included balance performance, comfortable gait speed and single and dual-task functional mobility.ResultsThree distinct profiles were identified; “Sedentary” (N = 68), “Light Movers” (N = 115), “Steady Movers” (N = 118). “Sedentary” included people with PD with high absolute and relative time spent in Sedentary behaviour (SB), little time light intensity physical activity (LIPA) and negligible moderate-to-vigorous physical activity (MVPA). “Light Movers” were people with PD with values close to the mean for all activity variables. “Steady Movers” spent less time in SB during midday, and more time in LIPA and MVPA throughout the day, compared to the other profiles. “Sedentary” people had poorer balance (P = 0.006), poorer functional mobility (P = 0.027) and were more likely to have fallen previously (P = 0.027), compared to “Light Movers. The Timed Up and Go test, an easily performed clinical test of functional mobility, was the only test that could distinguish between all three profiles.ConclusionDistinct PA profiles, with clear differences in how the time awake is spent exist among people with mild-moderate PD.

Daily physical activity and sedentary behaviour across occupational classifications in Canadian adults.

Adults spend a large proportion of their day at work. Physical activity (PA) and sedentary behaviour (SB) have been shown to vary considerably between occupations. The objective of this study is to describe occupational differences in accelerometer-measured and self-reported PA and SB for Canadian full-time workers. Using combined data from three cycles of the nationally representative Canadian Health Measures Survey (N = 4,080), three activity groups (high, intermediate, low) were created based on a composite ranking of accelerometer-derived steps, proportion of time spent sedentary (SED%) and moderate-to-vigorous intensity physical activity (MVPA) in bouts of ⋝10 minutes (MVPAbouted). Differences between groups were assessed for accelerometer-derived and self-reported PA and SB, and sociodemographic and clinical characteristics. On average, Canadians employed in full-time work were sedentary for 68.9% of their day (95% confidence interval [CI]: 68.3% to 69.6%), took 8,984 steps per day (95% CI: 8,719 to 9,249) and accumulated 79.5 minutes per week of MVPAbouted (95% CI: 71.1 to 87.9). Among Canadians employed in full-time work, 18.5% met the Canadian Physical Activity Guidelines. The high-activity group took significantly more steps and had a lower SED%, but spent a higher proportion of time in light-intensity PA compared with the intermediate- and low-activity groups. No differences were observed for MVPA. The low-activity group reported more recreational and active travel-related PA and leisure reading, while those in the high-activity group reported more work and domestic PA and leisure screen time. The majority of full-time working adults are not getting adequate MVPA and spend most of their day sedentary, regardless of occupation. Findings support workplace policies to improve MVPA levels among Canadian workers and to promote awareness for the potential benefit of occupation-specific messaging around PA and SB.

Temporal associations between physical activity, mental activity and fatigue dimensions in knee osteoarthritis: an exploratory intensive longitudinal study

ABSTRACT Background: Fatigue may include both physical and mental dimensions. Evidence suggests that physical and mental activity may influence fatigue in knee osteoarthritis (OA). However, how physical and mental activities relate to fatigue dimensions in knee OA is unclear. Purpose: This study estimated intra-day contributions of physical and mental fatigue to general fatigue and evaluated temporal associations between physical activity, mental activity and fatigue dimensions in knee OA. Methods: An intensive longitudinal study combined with ecological momentary assessment of mental activity intensity and fatigue dimensions was conducted on 23 participants with knee OA. Physical activity was monitored continuously with an accelerometer over 7 days. Results: Physical fatigue contributed 33% more to general fatigue earlier in the day than mental fatigue, and 11% more near the end of the day. Within-day, previous general fatigue significantly and negatively predicted: future step counts, light intensity physical activity time, and light intensity physical activity + standing time. We found a significant bidirectional association between mental activity and general fatigue, a positive association between mental activity and mental fatigue and a significant negative association between mental fatigue and mental activity. Conclusion: Within-day general fatigue may be a significant fatigue dimension that reduces physical activity. Conversely there was no evidence that physical activity might contribute to lower scores on any fatigue dimensions in this population. To manage general fatigue, physical and mental fatigue might have to be targeted more precisely at different time of the day.

Physical activity in early childhood education and care settings in a low-income, rural South African community: an observational study.

Research has not been conducted on physical activity in early child education and care (ECEC) settings in low-income, rural communities in South Africa. This study aimed to describe the physical activity environment of these settings and identify child and contextual factors associated with physical activity in these settings. By understanding physical activity in this environment, it will be possible to identify context-specific opportunities, including with teachers, to overcome potential challenges and maximise physical activity in a low- and middle-income country setting. The study was conducted in rural Bushbuckridge, Mpumalanga in 2014. Preschool-aged children (n=55) were recruited from five ECEC settings, including three preschools and two primary schools, where preschool-aged children are in their reception year, grade R. Preschool environment characteristics were assessed using an observational tool adapted from existing tools. Children's physical activity was assessed using the Observational System for Recording Physical Activity in Children - Preschool Version. Differences between preschool and grade R settings were assessed using χ2 analyses, and multinomial logistic regression analysis was used to determine factors associated with physical activity in the ECEC settings. The physical activity environment differed between preschool and grade R ECEC settings in terms of space (preschoolpgrade R, p<0.001). On average, children spent 28.7% of their day in the ECEC settings engaged in physical activity, of which 22.3% was moderate- to vigorous-intensity physical activity (MVPA). Children spent the greatest proportion of the day in sedentary activities (69.9%) and this differed significantly between preschool (63.2%) and grade R children (81.3%, p<0.001). Preschool children were significantly more active than grade R children, and spent greater proportions of time in light-intensity physical activity (8.6% v 2.7%, p<0.001) and MVPA (25.4% v 15.3%, p<0.001). Irrespective of ECEC setting, children were significantly more likely to participate in MVPA if they were outdoors (p=0.001), and significantly less likely to do MVPA if they were overweight/obese (p=0.006). These findings provide insight into child-level and contextual factors associated with preschool-aged children's physical activity within ECEC settings in a low-income, rural community in South Africa. Particularly, the physical and social features of ECEC settings are important in the promotion of physical activity. Findings from this study suggest that it is necessary to upskill and encourage teachers in ECEC settings to maximise opportunities for physical activity in rural low-income communities in South Africa.

Time Spent In Moderate- to Vigorous-intensity Physical Activity Is Associated With Intramuscular Adipose Tissue Content In Young Men

Physical inactivity induces decreases of skeletal muscle mass and increases content of the adipose tissue in humans. However, it is not well known that the relationships between daily physical activity and various types of adipose tissues such as intramuscular adipose tissue (IntraMAT), intermuscular adipose tissue (InterMAT) or subcutaneous adipose tissue (SAT). PURPOSE: To investigate relationship between daily physical activity and contents of IntraMAT, InterMAT and SAT in the thigh for young men. METHODS: Twenty healthy young men (24.5±4.8 years) participated in this study. Axial images of the mid-thigh were taken using magnetic resonance imaging. The cross-sectional area (CSA) of IntraMAT, InterMAT, SAT and skeletal muscle were measured. Daytime physical activity time was measured using an accelerometer on 14 consecutive days and summarized the activity time of two intensities; light-intensity (1.1-2.9 METs), and moderate- to vigorous-intensity (3.0-7.0 METs). RESULTS: In the accelerometer data, time spent in light-intensity physical activity was 672.4±74.6 min/day, and time spent in moderate-to vigorous-intensity physical activity was 96.6±30.5 min/day. Light-intensity physical activity time was not significantly correlated with contents of all adipose tissues in the thigh. The moderate- to vigorous-intensity physical activity time was correlated with IntraMAT content (r = -0.739, P < 0.01). On the other hand, moderate- to vigorous-intensity physical activity time was not significantly correlated with contents of InterMAT and SAT. Stepwise regression analysis was performed, with IntraMAT content as a dependent variable and age, body mass index, SAT CSA/body weight, skeletal muscle CSA/body weight, light-intensity physical activity time, moderate- to vigorous-intensity physical activity time as independent variables. As a result, skeletal muscle CSA/body weight and moderate- to vigorous-intensity physical activity time were independent variables (R2 = 0.655). CONCLUSIONS: These results suggest that moderate- to vigorous-intensity physical activity time was related to IntraMAT content only, skeletal muscle size and moderate- to vigorous-intensity physical activity time could be a major determinant of IntraMAT content in young men.

Physical function in older adults: Impacts of past and present physical activity behaviors.

While physical activity (PA) may counteract age-related functional decline and loss of independence at old age, to what extent physical function is influenced by past or present PA behaviors is currently unclear. Therefore, the aim of the study was to examine relationships between both past and present PA behaviors and components of physical function in older women. A physical function score based on the 6-minute walk test, squat jump, and single-leg-stance balance was aggregated in 60 older women (65-70years). Present PA behavior was assessed by accelerometry (Actigraph) and past leisure-time PA was self-reported, where times in sports-related activities and in walking were analyzed separately. Analysis of differences in physical function across tertiles of PA behaviors was adjusted by DXA-derived fat mass. Physical activity level at present age and engagements in sports-related activities before retirement age, excluding walking, were both associated (P<0.05) to physical function. Time spent in PA of at least moderate intensity was associated with physical function (P<0.05), whereas no corresponding relationships to either sedentary time or time in light intensity PA were observed. In conclusion, PA behaviors at present age and engagement in sports-related activities performed during adulthood are both related to physical function in older women. Being physically active at old age infers beneficial effects on physical function, even in individuals with a past or present sedentary lifestyle, which supports public health efforts aiming at increasing daily time in PA of at least moderate intensity to preserve physical function in older women.

Effects of prescribed aerobic exercise volume on physical activity and sedentary time in postmenopausal women: a randomized controlled trial

BackgroundPhysical activity has emerged as an important lifestyle factor for primary prevention of numerous diseases, including postmenopausal breast cancer. No study to date has assessed the acute and long-term effects of year-long aerobic exercise programs differing in prescribed exercise volume on physical activity and sedentary time in postmenopausal women. Therefore, we aimed to examine the effects of two moderate-vigorous intensity exercise doses on total, light and moderate-vigorous intensity physical activity times, and sedentary time in postmenopausal women during the year-long intervention and one year later.MethodsThe Breast Cancer and Exercise Trial in Alberta (BETA) was a two-center, two-arm, 12-month randomized controlled trial that included 400 previously inactive postmenopausal women randomized to either 150 (MODERATE) or 300 (HIGH) minutes/week of aerobic exercise. Physical activity and sedentary time were assessed at baseline, 6- (intervention mid-point), 12- (prior to end of intervention) and 24-months (follow-up) with waist-mounted accelerometers (Actigraph GTX3®). Self-reported activity and sedentary time at baseline, 12- and 24-months was also assessed (Past Year Total Physical Activity Questionnaire and SIT-Q). Intention-to-treat analyses were conducted using linear mixed models and adjusted for baseline variables.ResultsBoth physical activity interventions led to increases in objective and subjective measures of total and moderate-vigorous intensity/recreational physical activity time, coupled with decreases in sedentary time, at 6- and 12-months compared to baseline. Additionally, greater increases in accelerometry-derived total physical activity time at 6- and 12-months, and self-reported recreational activity time at 12-months, compared to baseline were noted in the HIGH versus MODERATE groups. Decreases in total, light and moderate-vigorous intensity physical activity time, and an increase in sedentary time, in both groups were noted at 24-months compared to 12-months. A decrease in light intensity physical activity time in both groups at 24-months compared to baseline was also noted.ConclusionThese findings have important health implications, suggesting that total physical activity time can be increased with greater volumes of prescribed exercise, but that additional support and resources could be used to promote the maintenance of these high levels of aerobic exercise participation following study completion.Trial registrationclinicaltrials.gov identifier: NCT01435005 (BETA Trial). Registred September 15th 2011 (retrospectively registered).

Replacing sedentary time with physical activity: a 15-year follow-up of mortality in a national cohort.

BackgroundSedentary behavior is associated with health risks in adults. The potential benefits of reducing sedentary time may be dependent not only on decrease per se, but also on the type of activity it replaces. Few longitudinal studies have investigated the effects on mortality when replacing objectively assessed sedentary time with another physical activity (PA) behavior.ObjectiveTo investigate the effects of replacing objectively assessed sedentary time with time in light-intensity PA or moderate-vigorous PA (MVPA) on all-cause mortality, cardiovascular disease (CVD) mortality or cancer mortality in a cohort with 15 years follow-up time.MethodsIn total, 851 women and men from the population-based Sweden Attitude Behaviour and Change study were included. Time spent sedentary, in light-intensity PA and in MVPA were assessed using an Actigraph 7164 accelerometer. Mortality data were obtained from Swedish registers. Cox proportional hazards models estimated hazard ratios (HR) of mortality with 95% confidence intervals (CI) and isotemporal substitution models were used to estimate the effect of replacing sedentary behavior with PA for the same amount of time.ResultsOver a follow-up of 14.2 years (SD 1.9) with 12,117 person-years at risk, 79 deaths occurred, 24 deaths from CVD, 27 from cancer, and 28 from other causes. Replacing 30 minutes/day of sedentary time with light-intensity PA was associated with significant reduction in all-cause mortality risk (HR: 0.89, 95% CI: 0.81–0.98) and CVD mortality risk (HR: 0.76, 95% CI: 0.63–0.92). Replacing 10 minutes of sedentary time with MVPA was associated with reduction in CVD mortality risk (HR: 0.62, 95% CI: 0.42–0.91). No statistically significant reductions were found for cancer mortality.ConclusionThis statistical modelling study suggests that replacing sedentary time with light-intensity PA could have beneficial effect on both all-cause mortality and CVD mortality. Replacing sedentary time with MVPA could reduce CVD mortality.

Association between objectively measured physical activity, chronic stress and leukocyte telomere length.

Physical activity (PA) attenuates chronic stress and age-related and cardiovascular disease risks, whereby potentially slowing telomere shortening. We aimed to study the association between seven-day objectively measured habitual PA, chronic stress and leukocyte telomere length. Study participants were African (N.=96) and Caucasian (N.=107) school teachers of the Sympathetic activity and Ambulatory Blood Pressure in Africans study. All lifestyle characteristics (including PA) were objectively measured. The general health questionnaire and serum cortisol were assessed as psychological and physical measures of chronic stress. Leukocyte telomere length was measured using the quantitative real-time polymerase chain reaction. Africans had significantly shorter telomeres (P<.0001) and greater psychological distress (P=0.001) than Caucasians, whereas no group difference was seen for cortisol levels. Higher age (ß=-0.28 [-0.40, -0.16, P≤0.000), higher alcohol consumption (ß=-0.21 [-0.36, -0.08], P=0.003) and increased central obesity (ß=-0.17 [-0.30, -0.03], P=0.017) were all significantly associated with shorter telomeres. Habitual PA of different intensity was not significantly associated with markers of chronic stress or telomere length. However, more time spent with light intensity PA time was significantly and independently correlated with lower waist circumference (r=-0.21, P=0.004); in turn, greater waist circumference was significantly associated shorter telomeres (β=-0.17 [-0.30, -0.03], P=0.017). Habitual PA of different intensity was not directly associated with markers of chronic stress and leukocyte telomere length in this biethnic cohort. However, our findings suggest that light intensity PA could contribute to lowered age-related disease risk and healthy ageing by facilitating maintenance of a normal waist circumference.

Objectively measured sedentary time and physical activity time across the lifespan: a cross-sectional study in four age groups

BackgroundFrom a health perspective it is suggested to promote a positive balance between time spent in light intensity physical activity (LIPA) and sedentary behaviour (SB) (i.e. spending more time in LIPA than time spent in SB). However, no studies have reported prevalence rates of the LIPA-SB balance yet. The aim of this study was to objectively investigate the time spent in SB, in LIPA and moderate-to-vigorous intensity physical activity (MVPA) in four Belgian age groups and to explore which proportion of the population had a favorable balance between LIPA and SB and combined this with recommended amount of MVPA.MethodsAccelerometer data from 7 cross-sectional studies (N=2083) in four age groups (preschoolers, primary schoolchildren, secondary schoolchildren and adults) were aggregated. Differences in SB and PA between age groups and between men and women were determined by two-way MANCOVA. LIPA-SB balance was calculated and participants were categorized into one of four groups: (1) positive LIPA-SB balance (LIPA> SB) & sufficient MVPA (2) negative LIPA-SB balance & sufficient MVPA (3) positive LIPA-SB balance & insufficient MVPA (4) negative LIPA-SB balance & insufficient MVPA.ResultsFor the total sample, 55% of the waking time was spent in SB, 39% in LIPA and 6% in MVPA. Differences in SB between age groups was dependent from gender (p<0.001). Further, a positive LIPA-SB balance was assessed in 18% of the total sample and only 10% combined this positive balance with recommended amount of MVPA. Secondary schoolgirls were most at risk, with only 1% of the sample combining a positive LIPA-SB balance with sufficient MVPA. Another risk group was the large proportion (43%) of adult men who combined sufficient MVPA with a negative LIPA-SB balance.ConclusionA high proportion of the Belgian population is at risk if taking into account both SB and PA levels. Secondary schoolgirls have the unhealthiest SB and PA profile and are therefore an important target group for interventions both increasing MVPA and decreasing SB. In men more attention should be given in promoting a positive LIPA-SB balance independently from their compliance with the MVPA guidelines.

Association of after-school physical activity levels and organized physical activity participation in Hong Kong children

The aims of this study were to 1) describe the children’s physical activity (PA) patterns during the after-school period and 2) to compare the type and intensity of activity during the after-school period of children with or without participation in organized PA programmes. The participants were 456 children from four primary schools in Hong Kong. Self-administered questionnaires were used to measure the PA pattern and intensity level of the children during the after-school period. Independent t-test and factorial ANOVA was used for data analysis. Results indicated that children engaged substantial time in light intensity PA during the after-school period. Children who participated in organized PA programmes spent fewer time blocks on light intensity PA and more time blocks in vigorous PA. The boys spent more time blocks on high intensity PA than the girls. A structured PA programme during the after-school period is a potential intervention strategy to increase children’s PA participation without using up the time intended for children’s homework.

Sedentary Behaviour And All Physical Activity Intensities Are Associated With Disease Risk

PURPOSE. With evidence suggesting that physical activity (PA), sedentary behaviour (SB), including sleep duration, it is important to adopt an all encompassing lifestyle approach when assessing the influence of these behaviours on health. The aim of this study was to assess the relationship between PA, SB and sleep, measured concurrently in UK adults on various disease risk outcomes. METHODS. PA and SB were measured using an ActiGraph GT1M accelerometer over a period of 9 days, in a sample of 78 adults (62% female, BMI = 25.4 ± 4.4kg/m2, age = 38.3 ± 14.1). Time spent in bed and sleep duration were recorded throughout using a sleep diary. Participant's height, weight, BMI, body composition, waist circumference and blood pressure were taken at the outset. Associations between time spent in SB, and time in light and moderate-to-vigorous PA (MVPA), and the disease risk factors were analysed using correlation coefficients in PASW 18.0. RESULTS. The mean proportion of time spent in SB, light intensity PA, MVPA and time spent asleep over a 24 hour period were 48% (691.2 ± 84.8 mins), 20% (288 ± 76.1 mins), 3% (43.2 ± 24.8 mins) and 29% (417.6 ± 38.5 mins), respectively. Increased time in light intensity PA was associated with reduced BMI (r2 = 0.06), body fat (r2 = 0.06), waist circumference (r2 = 0.05) (all p < 0.05) and systolic (r2 = 0.10) and diastolic blood pressure (r2=0.20) (all p<0.05), whilst increased time in SB was associated with increased systolic (r2=0.09) and diastolic blood pressure (r2=0.20) (all p < 0.01). Increased time in MVPA was associated with reduced fat percentage (r2= 0.10, p<0.05). No significant associations were observed between time in bed and sleep duration with the disease risk factors. CONCLUSIONS. In the sample studied, increased time spent in light intensity PA as well as MVPA and less sedentary behaviour were all associated with less risk for disease. Although evidence suggests that for beneficial effects on health, moderate intensity activity is needed, this study adds to the emerging limited evidence highlighting the potential added beneficial effects of light intensity PA on health. Programmes focussing on moving people from less sedentary behaviour to any level of intensity of physical activity could therefore be useful in reducing risk for chronic disease.

Endothelic Nitric Oxide (eNOS) Genetic Variants Associate with Physical Activity Levels among Young Caucasian Adults

PURPOSE: Over 50% of adults do not engage in regular physical activity (PA). Genetic factors account for 32-85% of the variation in PA levels, but evidence identifying specific gene variants that influence habitual PA levels is limited. Thus, we examined associations among three genetic variants of the eNOS gene (-786T>C, rs2070744; -922A>G, rs1800779; 894G>T, rs1799983) and PA among healthy, young Caucasian adults. METHODS: Subjects (n=577, age 24.3±8.0yr, body mass index (BMI) 24.3±4.5kg·m-2) were genotyped for eNOS-786 T>C (n=308, TT n=128, TC n=147, CC n=33), -922 A>G (n=368, AA n=145, AG n=183, GG n=42), and 894 G>T (n=393, GG n=195, GT n=165, TT n=33). Subjects completed the Paffenbarger PA Questionnaire. PA phenotypes included; hr/wk spent in light, moderate and vigorous intensity PA, and sitting. Repeated measures ANCOVA tested associations among genetic variants and PA phenotypes by gender with age and BMI as covariates. Associations did not differ by gender so data are presented for the total sample. RESULTS: Adults with the eNOS 894 TT genotype reported less time in vigorous intensity PA than those with the GT and GG genotypes (4.3±1.3, 7.6±0.6, and 8.0±0.6hr/wk, respectively) (p=0.037). Adults with eNOS 894 TT genotype also reported spending more time in light intensity PA than adults with GT and GG genotypes (43.3±2.7, 36.4±1.2, and 34.5±1.1hr/wk, respectively) (p=0.009). In addition, those with eNOS 894 GT and GG genotypes reported to sit more than adults with the TT genotype (48.2±1.4, 45.9±1.3, and 38.3±3.2hr/wk, respectively) (p=0.014). CONCLUSIONS: Adults with the eNOS 894 TT genotype reported more time in light intensity PA, less time in vigorous intensity PA, and less time sitting than carriers of G allele. The vascular effects of regular episodic shear stress differs by PA intensity and may account for these eNOS 894 T>G genotype associations. However, our findings should be replicated in a prospective study designed to investigate the direct impact of PA on vascular function to determine if these suppositions are true. Supported by NIH-NINDS R01 NS40606-02 and the University of Connecticut. Center for Health, Intervention and Prevention.

Comparison of Kenz Lifecorder EX and ActiGraph Accelerometers in 10-yr-old Children

A new accelerometer, the Kenz Lifecorder EX (LC; Suzuken Co. Ltd, Nagoya, Japan), offers promise as a feasible monitor alternative to the commonly used Actigraph (AG: Actigraph LLC, Fort Walton Beach, FL). This study compared the LC and AG accelerometers and the Yamax SW-200 pedometer (DW) under free-living conditions with regard to children's steps taken and time in light-intensity physical activity (PA) and moderate to vigorous PA (MVPA). Participants (N=31, age=10.2 +/- 0.4 yr) wore LC, AG, and DW monitors from arrival at school (7:45 a.m.) until they went to bed. Time in light and MVPA intensities were calculated using two separate intensity classifications for the LC (LC_4 and LC_5) and four classifications for the AG (AG_Treuth, AG_Puyau, AG_Trost, and AG_Freedson). Both accelerometers provided steps as outputs. DW steps were self-recorded. Repeated-measures ANOVA was used to assess overlapping monitor outputs. There was no difference between DW and LC steps (Delta=200 steps), but a nonsignificant trend was observed in the pairwise comparison between DW and AG steps (Delta=1001 steps, P=0.058). AG detected significantly greater steps than the LC (Delta=801 steps, P=0.001). Estimates of light-intensity activity minutes ranged from a low of 75.6 +/- 18.4 min (LC_4) to a high of 309 +/- 69.2 min (AG_Treuth). Estimates of MVPA minutes ranged from a low of 25.9 +/- 9.4 min (LC_5) to a high of 112.2 +/- 34.5 min (AG_Freedson). No significant differences in MVPA were seen between LC_5 and AG_Treuth (Delta=4.9 min) or AG_Puyau (Delta=1.7 min). The LC detected a comparable number of steps as the DW but significantly fewer steps than the AG in children. Current results indicate that the LC_5 and either AG_Treuth or AG_Puyau intensity derivations provide similar mean estimates of time in MVPA during-free living activity in 10-yr-old children.