Accelerometer-measured physical activity in mid-age Australian adults

BACKGROUND: Raw data from accelerometers can provide valuable insights into specific attributes of physical activity, such as time spent in intensity-specific activity. The aim of this study was to describe physical activity assessed with raw data from triaxial wrist-worn accelerometers in mid-age Australian adults. METHODS: Data were from 700 mid-age adults living in Brisbane, Australia (mean age: 60.4; SD:7.1 years). Data from a non-dominant wrist worn triaxial accelerometer (Actigraph wGT3X-BT), expressed as acceleration in gravitational equivalent units (1 mg = 0.001 g), were used to estimate time spent in moderate-vigorous intensity physical activity (MVPA; >100 mg) using different bout criteria (non-bouted, 1-, 5-, and 10-min bouts), and the proportion of participants who spent an average of at least one minute per day in vigorous physical activity. RESULTS: Mean acceleration was 23.2 mg (SD: 7.5) and did not vary by gender (men: 22.4; women: 23.7; p-value: 0.073) or education (p-value: 0.375). On average, mean acceleration was 10% (2.5 mg) lower per decade of age from age 55y. The median durations in non-bouted, 1-min, 5-min and 10-min MVPA bouts were, respectively, 68 (25th -75th : 45–99), 26 (25th -75th : 12–46), 10 (25th -75th : 3–24) and 8 (25th -75th : 0–19) min/day. Around one third of the sample did at least one minute per day in vigorous intensity activities. CONCLUSION: This population-based cohort provided a detailed description of physical activity based on raw data from accelerometers in mid-age adults in Australia. Such data can be used to investigate how different patterns and intensities of physical activity vary across the day/week and influence health outcomes

The association between sedentary leisure and physical activity in middle-aged adults

Aim The aim of this study was to examine the association between time spent in sedentary leisure and physical activity level in mid-aged men and women

Is physical inactivity associated with depressive symptoms among adolescents with high screen time? Evidence from a developing country

Background Increasing levels of screen use and physical inactivity in developing countries may be deleterious for adolescent mental health. This study aimed to examine how physical inactivity is associated with concurrent depressive symptoms among adolescents with high recreational screen time in Bangladesh. Methods A self-administered survey was conducted among 898 secondary school students of Dhaka city, Bangladesh. High screen-time was assessed using the Adolescent Sedentary Activity Questionnaire (ASAQ), with a cut-off of >2\ua0h/day. Scores ≥10 on the 10-item Center for Epidemiological Studies Depression Scale (CESD10) suggested depressive symptoms. The Three-Day Physical Activity Recall (3DPAR) instrument was used to estimate physical activity, with those doing ≤60\ua0min/day of moderate-vigorous physical activity (MVPA) classified as not meeting MVPA recommendations. Of the 599 adolescents who were determined to have high recreational screen time (>2\ua0h/day), 505 completed the CESD10, and form the basis for this analysis. Results Of the adolescents with high recreational screen time, 32% did not meet MVPA recommendations and 25% reported depressive symptoms. Generalized estimating equations modelling on CESD scores showed that depressive symptoms were more prevalent among adolescents with high screen time who also did not meet MVPA recommendations (OR 2.37; 95% CI: 1.23–4.59), after adjusting for a set of confounders including sociodemographic, psychosocial and lifestyle factors. Conclusions Adolescents in Dhaka city with high recreational screen time and not meeting physical activity recommendations are also likely to have depressive symptoms. More research is needed to understand the causal directions of these relationships

Identifying patterns of item missing survey data using latent groups: An observational study

Objectives: To examine whether respondents to a survey of health and physical activity and potential determinants could be grouped according to the questions they missed, known as ‘item missing’. Design: Observational study of longitudinal data. Setting: Residents of Brisbane, Australia. Participants: 6901 people aged 40–65 years in 2007. Materials and methods: We used a latent class model with a mixture of multinomial distributions and chose the number of classes using the Bayesian information criterion. We used logistic regression to examine if participants’ characteristics were associated with their modal latent class. We used logistic regression to examine whether the amount of item missing in a survey predicted wave missing in the following survey. Results: Four per cent of participants missed almost one-fifth of the questions, and this group missed more questions in the middle of the survey. Eighty-three per cent of participants completed almost every question, but had a relatively high missing probability for a question on sleep time, a question which had an inconsistent presentation compared with the rest of the survey. Participants who completed almost every question were generally younger and more educated. Participants who completed more questions were less likely to miss the next longitudinal wave. Conclusions: Examining patterns in item missing data has improved our understanding of how missing data were generated and has informed future survey design to help reduce missing data

Prevalence and sociodemographic patterns of physical activity among Bangladeshi young adult

Background: Physical activity offers physical and psychosocial health benefits that are important during young adulthood and later in life. However, little is known about the physical activity of young adults in low- and middle-income countries. The purpose of this study was to estimate the participation of physical activity in Bangladeshi young adults and to assess differences by gender, age and family income. Methods: This cross-sectional study with a self-administered survey used a convenience sample of 573 young adults aged 18\u201324 years from six purposively selected universities in Dhaka City, Bangladesh. Data were collected during September\u2013November 2015. Medians and their interquartile ranges of weekly time spent in total physical activity, and in different domains of physical activity, were computed. Non-parametric equality of medians test was used to examine gender differences in the median values. Chi-square test and Fisher\u2019s exact test were used to examine gender differences in the prevalence of meeting physical activity recommendations and frequency of participation in different leisure-time physical activities, and differences in meeting the activity recommendations by age and family income. Results: Seventeen percent of the participants were meeting moderate-to-vigorous physical activity (MVPA) recommendations with a significantly higher proportion of males than females (27 vs. 6%, p < .0001). Median duration of MVPA was significantly higher (p < .0001) for males [120 min/week (80, 190)] than females [90 min/week (50, 120)]. Jogging/running was the most commonly reported leisure-time physical activity, with 20% of males and 12% of females doing this at least once a week. Age and family income were not significantly associated with meeting MVPA recommendations. Conclusions: Four out of five young adults in Dhaka City did not meet the physical activity recommendations. Additional population-based studies, including regional and metropolitan areas, and using objective measurement, are needed to understand the physical activity patterns of Bangladeshi young adults

Gender differences in physical activity motivators and context preferences: A population-based study in people in their sixties

© 2017 The Author(s). Background: Although regular participation in physical activity (PA) has health benefits across the life span, the proportion of people doing sufficient activity for these benefits decreases with age. The aim of this study was to identify motivating factors and context preferences for PA in people in their sixties, and to examine gender differences in these factors. Methods: Data were used from people aged 60-67 years who responded to a mail survey in Brisbane, Australia, in 2009. Respondents indicated their agreement/disagreement with seven PA motivators and 14 PA context preferences. Data were analyzed using multi-level multinomial logistic regression, adjusted for sociodemographic and health variables, and PA level. Results: Of the 1845 respondents, 59% was female. Based on self-reported PA, one in three respondents (35%) did not meet the PA guidelines of at least 150 min of moderate intensity PA per week. The three leading motivating factors for both women and men were to prevent health problems, to feel good and to lose weight. Women were more likely than men to be motivated by improving appearance (OR 2.93, 95%CI 2.07-4.15), spending time with others (1.76, 1.31-2.37), meeting friends (1.76, 1.31-2.36) or losing weight (1.74, 1.12-2.71). The three leading context preferences for both women and men were for activities close to home, at low cost and that could be done alone. Women were more likely than men to prefer activities that are with people of the same sex (OR 4.67, 95%CI 3.14-6.94), supervised (2.79, 1.94-4.02), with people the same age (2.00, 1.43-2.78) and at a fixed time (1.42, 1.06-1.91). Women were less likely than men to prefer activities that are competitive (OR 0.32, 95%CI 0.22-0.46), are vigorous (0.33, 0.24-0.47), require skill and practice (0.40, 0.29-0.55) and done outdoors (0.51, 0.30-0.86). Conclusion: Although there was overlap in motivating factors and context preferences for PA in women and men aged 60-67 years, there were also marked gender differences. These results suggest that PA options for people in their sixties should be tailored to meet gender specific interests in order to promote PA participation in this rapidly growing population group

Lorentz-Lorenz Coefficient, Critical Point Constants, and Coexistence Curve of 1,1-Difluoroethylene

We report measurements of the Lorentz-Lorenz coefficient density dependence, the critical temperature, and the critical density, of the fluid 1,1-difluoroethylene. Lorentz-Lorenz coefficient data were obtained by measuring refractive index and density of the same fluid sample independently of one another. Accurate determination of the Lorentz-Lorenz coefficient is necessary for transformation of refractive index data into density data from optics-based experiments on critical phenomena of fluid systems done with different apparatus, with which independent measurement of the refractive indes and density is not possible. Measurements were made along the coexistence curve of the fluid and span the density range 0.01 to 0.80 g/cc. The Lorentz-Lorenz coefficient results show a stronger density dependence along the coexistence curve than previously observed in other fluids, with a monotonic decrease from a density of about 0.2 g/cc onwards, and an overall variation of about 2.5% in the density range studied. No anomaly in the Lorentz-Lorenz coefficient was observed near the critical density. The critical temperature is measured at Tc=(302.964+-0.002) K (29.814 C) and the measured critical density is (0.4195+-0.0018)g/cc.Comment: 14 pages, 6 figures, MikTeX 2.4, submitted to Physical Review

Defining a valid day of accelerometer monitoring in adults with mental illness

Introduction A valid day of accelerometry is commonly defined as an absolute duration of wear time. Data processing inconsistencies can arise when using absolute valid-day criteria for adults with varied waking hours. The aim was to compare the use of absolute and relative valid-day criteria in a sample of adults with mental illness. Methods Data were from 99 non-institutionalised adults with mental illness. Participants were asked to wear an ActiGraph GT3X+ accelerometer continuously for seven days, and to note sleep and non-wear times. Absolute valid-day criteria were defined as a set number of hours/day, and relative criteria as a proportion of waking hours. The mean waking duration, non-wear time, and time spent in physical activity (PA) and sedentary behaviour (SB), were derived from accelerometer data, and compared for a range of absolute and relative criteria. The potential inaccuracy of PA and SB estimates were also estimated. Results Use of absolute criteria systematically biased the sample toward those with longer waking hours, and resulted in a median of 86% (IQR = 47%-198%) more non-wear time than relative criteria. The potential inaccuracy of SB was from -2.5% to 0% with relative criteria, and from -2.2% to 10.6% for absolute criteria. Conclusions For participant samples with varied waking hours, such as adults with mental illness, a valid-day criterion should be based on the proportion of waking hours, rather than the absolute time. The specific valid-day criterion should be chosen for each study independently, and be accompanied with a measure of the non-wear time

Physical activity and quality of life in older women with a history of depressive symptoms

Physical activity (PA) is positively associated with health-related quality of life (HRQL) in older adults. It is not evident whether this association applies to older adults with poor mental health. This study examined associations between PA and HRQL in older women with a history of depressive symptoms. Participants were 555 Australian women born in 1921–1926 who reported depressive symptoms in 1999 on a postal survey for the Australian Longitudinal Study on Women's Health. They completed additional surveys in 2002, 2005 and 2008 that assessed HRQL and weekly minutes walking, in moderate PA, and in vigorous PA. Random effects mixed models were used to examine concurrent and prospective associations between PA and each of 10 HRQL measures (eight SF-36 subscales; two composite scales). In concurrent models, higher levels of PA were associated with better HRQL (p\ua0\ua03 point differences) were evident for physical functioning, general health, vitality and social functioning. For women in their 70s–80s with a history of depressive symptoms, PA is positively associated with HRQL concurrently, and to a lesser extent prospectively. This study extends previous work by showing significant associations in older women with a history of depressive symptoms. Incorporating PA into depression management of older women may improve their HRQL

Do walking strategies to increase physical activity reduce reported sitting in workplaces: a randomized control trial

Background Interventions designed to increase workplace physical activity may not automatically reduce high volumes of sitting, a behaviour independently linked to chronic diseases such as obesity and type II diabetes. This study compared the impact two different walking strategies had on step counts and reported sitting times. Methods Participants were white-collar university employees (n = 179; age 41.3 ± 10.1 years; 141 women), who volunteered and undertook a standardised ten-week intervention at three sites. Pre-intervention step counts (Yamax SW-200) and self-reported sitting times were measured over five consecutive workdays. Using pre-intervention step counts, employees at each site were randomly allocated to a control group (n = 60; maintain normal behaviour), a route-based walking group (n = 60; at least 10 minutes sustained walking each workday) or an incidental walking group (n = 59; walking in workday tasks). Workday step counts and reported sitting times were re-assessed at the beginning, mid- and endpoint of intervention and group mean± SD steps/day and reported sitting times for pre-intervention and intervention measurement points compared using a mixed factorial ANOVA; paired sample-t-tests were used for follow-up, simple effect analyses. Results A significant interactive effect (F = 3.5; p < 0.003) was found between group and step counts. Daily steps for controls decreased over the intervention period (-391 steps/day) and increased for route (968 steps/day; t = 3.9, p < 0.000) and incidental (699 steps/day; t = 2.5, p < 0.014) groups. There were no significant changes for reported sitting times, but average values did decrease relative to the control (routes group = 7 minutes/day; incidental group = 15 minutes/day). Reductions were most evident for the incidental group in the first week of intervention, where reported sitting decreased by an average of 21 minutes/day (t = 1.9; p < 0.057). Conclusion Compared to controls, both route and incidental walking increased physical activity in white-collar employees. Our data suggests that workplace walking, particularly through incidental movement, also has the potential to decrease employee sitting times, but there is a need for on-going research using concurrent and objective measures of sitting, standing and walking