Vigorous Physical Activity Time Research Articles

Aerobic exercise training normalizes central blood pressure regulation after oral glucose loading in overweight/obese men

ABSTRACTCentral systolic blood pressure (cSBP) decreases after a meal or glucose challenge, but this response is impaired in obesity-related disorders. We investigated whether aerobic exercise training improves cSBP regulation during an oral glucose tolerance test (OGTT) in overweight/obese men. Thirteen overweight/obese men and six normal-weight men (as an alternative comparison instead of a no-exercise group) completed a 12-week aerobic exercise training program. Before and after the program, cSBP (i.e., radial second systolic pressure) was measured using an applanation tonometry at fasting and both 60 min and 120 min after 75 g glucose loading. Before and during the program, physical activity (PA) time was recorded using a tri-axial accelerometer. Pre-training, cSBP was significantly decreased with glucose loading in normal-weight men, while cSBP did not change in overweight/obese men. Post-training, a significant decrease in cSBP was observed in both groups following glucose loading. In addition, the increase in vigorous PA time during the exercise program was significantly correlated to the increase in area above the curve for cSBP during OGTT (demonstrating an improvement in the cSBP response to glucose loading) after the exercise program. These findings may provide novel insights into the role of PA in reducing the cardiovascular risk in obesity.

Development of Step-Count Cut Points for School-Day Vigorous Physical Activity.

Background No study has established step-count cut points for varying amounts of accelerometer-assessed vigorous physical activity (VPA) accrued during the school day in children. The purpose of this study was to establish step-count cut points for discriminating children meeting VPA in 5 minutes, 10 minutes, 15 minutes, and 20 minutes per 7-hour school day. Methods Participants were a convenience sample of 1,053 children (mean age = 8.4 (1.8) years) recruited from 5 schools from the Mountain West region of the USA. Data within students were observed across multiple semesters totaling 2,119 separate observations. Step counts and time in VPA were assessed using ActiGraph wGT3X-BT triaxial accelerometers that were worn during the entirety of a 7-hour school day for one school week. Average censored step counts and minutes in VPA were calculated across 3 to 5 days. Receiver operating characteristic (ROC) curves were employed to derive step counts via calculation of the maximum Youden J statistic. Results Area-under-the-curve (AUC) scores ranged from AUC = 0.81 (95% CI: 0.78–0.83; p < 0.001) for meeting at least 5 minutes of VPA to AUC = 0.94 (95% CI: 0.88–1.00, p < 0.001) for meeting at least 20 minutes of VPA. Approximately 3,460 steps best discriminated children meeting at least 5 minutes of VPA (sensitivity = 74.0%, specificity = 74.0%, and accuracy = 74.1%) and approximately 5,628 steps best discriminated children meeting at least 20 minutes per day of VPA (sensitivity = 85.7%, specificity = 95.1%, and accuracy = 95.1%). Conclusion Step counts can discriminate with reasonable accuracy children that meet at least 5 minutes of school-day VPA and with strong accuracy children that meet 20 minutes of school-day VPA.

Individual and environmental correlates of objectively measured sedentary time in Dutch and Belgian adults.

As the detrimental health effects of sedentary behaviour are well established, insight into the individual and environmental factors that influence adults’ sedentary behaviour is needed. Most studies to date rely on self-reported measures of sedentary time. Therefore, the aim of the current study was to examine individual and environmental correlates of objectively measured sedentary time in Dutch and Belgian adults. Between March and August 2014, Belgian (n = 133) and Dutch (n = 223) adults, recruited as sub-sample of the SPOTLIGHT survey, wore an ActiGraph accelerometer to provide objectively measured sedentary and moderate to vigorous physical activity time. Participants completed a questionnaire assessing sociodemographic (country of residence, age, gender and educational level), lifestyle (sleep, smoking, sugar-containing beverage consumption, alcohol intake), health (body mass index, self-rated health), work (employment status and type of work), happiness, physical environmental (owning a car, number of screens, socioeconomic status and residential density) and social environmental factors (social network, social cohesion). Univariate and multivariable regression analyses showed that Belgian participants had a lower odds of being sedentary for at least 9 hours per day compared to Dutch participants. Women, older participants and those meeting the WHO recommendation for physical activity were also less likely to sit for 9 hours or more per day. Participants doing (heavy) manual work or being in education, homemaker, unemployed had lower odds of being sedentary for at least 9 hours per day compared to participants with a sitting job. Those with a higher self-reported social network also had lower odds for sedentary time. No associations between physical and other social environmental characteristics and sedentary time were found. Our findings add to the growing evidence of factors associated with prolonged sedentary time in adults. These findings may be used to inform the development of strategies and interventions aimed at reducing sedentary time, and to identify high risk groups.

A Community-Based Physical Activity Counselling Program for People With Knee Osteoarthritis: Feasibility and Preliminary Efficacy of the Track-OA Study.

BackgroundPhysical activity can improve health outcomes in people with knee osteoarthritis (OA); however, participation in physical activity is very low in this population.ObjectiveThe objective of our study was to assess the feasibility and preliminary efficacy of the use of wearables (Fitbit Flex) and telephone counselling by a physical therapist (PT) for improving physical activity in people with a physician-confirmed diagnosis of knee OA, or who have passed 2 validated criteria for early OA. MethodsWe conducted a community-based feasibility randomized controlled trial. The immediate group (n=17) received a brief education session by a physical therapist, a Fitbit Flex activity tracker, and a weekly telephone call for activity counselling with the physical therapist. The delayed group (n=17) received the same intervention 1 month later. All participants were assessed at baseline (T0), and the end of 1 month (T1) and 2 months (T2). Outcomes were (1) mean moderate to vigorous physical activity time, (2) mean time spent on sedentary behavior, (3) Knee Injury and Osteoarthritis Outcome Score (KOOS), and (4) Partners in Health Scale. Feasibility data were summarized with descriptive statistics. We used analysis of covariance to evaluate the effect of the group type on the outcome measures at T1 and T2, after adjusting for blocking and T0. We assessed planned contrasts of changes in outcome measures over measurement periods.ResultsWe identified 46 eligible individuals; of those, 34 (74%) enrolled and no one dropped out. All but 1 participant adhered to the intervention protocol. We found a significant effect, with the immediate intervention group having improved in the moderate to vigorous physical activity time and in the Partners in Health Scale at T0 to T1 compared with the delayed intervention group. The planned contrast of the immediate intervention group at T0 to T1 versus the delayed group at T1 to T2 showed a significant effect in the sedentary time and the KOOS symptoms subscale, favoring the delayed group.ConclusionsThis study demonstrated the feasibility of a behavioral intervention, supported by the use of a wearable device, to promote physical activity among people with knee OA.Trial RegistrationClinicalTrials.gov NCT02313506; https://clinicaltrials.gov/ct2/show/NCT02313506 (Archived by WebCite at http://www.webcitation.org/6r4P3Bub0)

Decreased Vigorous Physical Activity in School-Aged Children with Human Immunodeficiency Virus in Johannesburg, South Africa

To describe physical activity in South African children with and without HIV. Study measurements were obtained in 218 children with perinatal HIV and 180 children without HIV aged 5-9years in a study conducted in Johannesburg, South Africa. Weight-for-age z-score, height-for-age z-score, frequency and duration of moderate and vigorous physical activity, and sedentary behaviors were obtained. These measurements were compared between children with and without HIV. Weight-for-age z-score and height-for-age z-score were significantly lower for children with HIV compared with those without HIV. Among children who attended school, fewer children with HIV than children without HIV participated in physical education (41% vs 64%; P=.0003) and organized after-school sports (38% vs 64%; P<.001). The proportion of children in both groups meeting World Health Organization recommendations for physical activity was similar (84% overall); however, girls with HIV spent less time in vigorous physical activity than girls without HIV (420 vs 780minutes/week; P=.001). This difference remained significant even when girls with a medical condition with the potential to limit physical activity were excluded, and after adjusting for age. Time spent in sedentary behaviors did not differ significantly between the two groups. Although children with HIV with well-controlled disease after initiating antiretroviral therapy early in life achieve high levels of physical activity, vigorous physical activity is lower in girls with HIV than in healthy controls. This finding may reflect lower participation in school-based physical education and organized after-school physical activity.

A Web-Based, Social Networking Physical Activity Intervention for Insufficiently Active Adults Delivered via Facebook App: Randomized Controlled Trial.

BackgroundOnline social networks offer considerable potential for delivery of socially influential health behavior change interventions.ObjectiveTo determine the efficacy, engagement, and feasibility of an online social networking physical activity intervention with pedometers delivered via Facebook app.MethodsA total of 110 adults with a mean age of 35.6 years (SD 12.4) were recruited online in teams of 3 to 8 friends. Teams were randomly allocated to receive access to a 50-day online social networking physical activity intervention which included self-monitoring, social elements, and pedometers (“Active Team” Facebook app; n=51 individuals, 12 teams) or a wait-listed control condition (n=59 individuals, 13 teams). Assessments were undertaken online at baseline, 8 weeks, and 20 weeks. The primary outcome measure was self-reported weekly moderate-to-vigorous physical activity (MVPA). Secondary outcomes were weekly walking, vigorous physical activity time, moderate physical activity time, overall quality of life, and mental health quality of life. Analyses were undertaken using random-effects mixed modeling, accounting for potential clustering at the team level. Usage statistics were reported descriptively to determine engagement and feasibility.ResultsAt the 8-week follow-up, the intervention participants had significantly increased their total weekly MVPA by 135 minutes relative to the control group (P=.03), due primarily to increases in walking time (155 min/week increase relative to controls, P<.001). However, statistical differences between groups for total weekly MVPA and walking time were lost at the 20-week follow-up. There were no significant changes in vigorous physical activity, nor overall quality of life or mental health quality of life at either time point. High levels of engagement with the intervention, and particularly the self-monitoring features, were observed.ConclusionsAn online, social networking physical activity intervention with pedometers can produce sizable short-term physical activity changes. Future work is needed to determine how to maintain behavior change in the longer term, how to reach at-need populations, and how to disseminate such interventions on a mass scale.Trial RegistrationAustralian New Zealand Clinical Trials Registry (ANZCTR): ACTRN12614000488606; https://www.anzctr.org.au/Trial/Registration/TrialReview.aspx?id=366239 (Archived by WebCite at http://www.webcitation.org/6ZVtu6TMz).

Prevalence Of Physical Activity And Sedentary Behaviors Of The U.S. Working Populations

PURPOSE: To estimate the prevalence of physical activity (PA) and sedentary behaviors of the US working adults by occupation. METHOD: Using the data collected from the National Health and Nutrition Examination Survey (NHANES, 2009-2010), the relationships between PA and sedentary behaviors of 3,288 working adults (≥ 20 yrs., with a mean of 43.14 and SD of 13.97 yrs.; 53.76% male) and their occupations were analyzed using multiple logistic regressions. RESULTS: When using % not meeting PA guideline (moderate to vigorous PA time ≥ 150 min/wk.) as the “less active” criterion and “arts, design, entertainment, sports, media” occupations (26.90% not meeting PA guideline) as a reference, workers in social services (52.94%, Odds Ratio(OR) = 3.06, 95% CI: 3.046-3.068), computer occupations (45.58%, OR = 2.28, 95% CI: 2.269-2.284), healthcare support (41.53%, OR = 1.93, 95% CI: 1.924-1.937), and protective services (40.83, OR = 1.98, 95% CI: 1.924-1.937) had the highest prevalence of less active behavior. Similarly, when using above 75th percentile in sedentary time (≥480 minutes in one typical day) and “arts, design, entertainment, sports, media” occupations (32.48% above 75th percentile in sedentary time) as a reference, workers in computer occupations (76.82%, OR = 6.89, 95% CI: 6.865-6.911), legal occupations (73.65%, OR = 5.81, 95% CI: 5.781-5.838), business related occupations (55.16%, OR = 2.56, 95% CI: 2.549-2.565), and engineering (49.93%, OR = 2.07, 95% CI: 2.065-2.08) had the highest prevalence of sedentary behavior. CONCLUSION: Professionals in social services, computer, and healthcare occupations are inclined to have a higher possibility of being less active. Workers in computer, legal, and business related occupations tended to have a higher risk of being more sedentary. Worksite targeted PA promotions, therefore, are extremely important for these occupations.

Youth Sport Practice Model Gets More Kids Active with More Time Practicing Skills (Un modelo de entrenamiento deportivo para aumentar los niveles de actividad de los jóvenes y de tiempo de práctica de habilidades)

Abstract. Due to the increasing number of children participating in sport, sport clubs and organizations have been identified as an important setting to facilitate physical activity and health promotion. The purpose of this study was to examine whether new national policies for sport practice increases physical activity time without compromising skill development time. Two comparative samples of youth sport leagues with contrasting sport practice models were evaluated for one year. Eighty-two recreational league hockey practices (ages 9-10). Of the practices, 43 used the new approach while 39 operated under a traditional structure. Momentary time sampling was used to measure player physical activity levels and the practice context in which they occur. A Metabolic Equivalent of Task (MET) score was calculated for each practice. Participants spent 44% of practice time engaged in sedentary activities, 33% in moderate physical activity, and 23% in vigorous physical activity. While individual minutes in MVPA and MET scores did not differ significantly between the practice types, new model practices provided overall higher MET hours than traditional practices. New model practices also accommodated approximately 60% more players while having twice as many coaches, a lower player-to-coach ratio, higher percentage of time in vigorous physical activity, and more time dedicated to skill drills/activities. Findings suggest sport practices can be structured to facilitate high levels of physical activity for more children without compromising attention to skill development and instruction.Resumen. Objetivo: Debido al creciente número de niños que participan en el deporte, los clubes y organizaciones deportivas han sido identificados como un marco importante para facilitar la actividad física y promoción de la salud. El objetivo de este estudio fue examinar si las nuevas políticas nacionales para la práctica del deporte aumentan el tiempo de actividad física sin comprometer el tiempo de desarrollo de habilidades. Se evaluaron durante un año dos muestras comparativas de las ligas deportivas juveniles con modelos contrapuestos de entrenamientos en el deporte. Métodos: Ochenta y dos practicantes a nivel recreativo de la liga de hockey (edades entre 9-10 años). De los entrenamientos, 43 utilizaron el nuevo enfoque mientras que en 39 se trabajó con una estructura tradicional. El muestreo de tiempo momentáneo se utilizó para medir los niveles de actividad física del jugador y el contexto de la práctica en que se producen. Se calculó la puntuación de un equivalente metabólico de tareas (MET) de cada entrenamiento. Resultados: Los participantes dedicaron un 44% del tiempo de la práctica a actividades sedentarias, un 33% en actividad física moderada y el 23% en actividad física vigorosa. Mientras los minutos individuales en AFMV y puntuaciones en MET no difieren significativamente entre los tipos de entrenamiento, los entrenamientos en el nuevo modelo proporcionan valores superiores de MET que los entrenamientos tradicionales. Los entrenamientos del nuevo modelo también acomodan aproximadamente un 60% más de jugadores al tener el doble de entrenadores, un menor ratio de jugador a entrenador, mayor porcentaje de tiempo en actividades físicas vigorosas, y más tiempo dedicado al desarrollo de ejercicios/actividades. Conclusiones: Los resultados sugieren que los entrenamientos deportivos pueden ser estructurados para facilitar altos niveles de actividad física para más niños sin comprometer la atención sobre el desarrollo de habilidades y la enseñanza.

The impact of playworks on boys' and girls' physical activity during recess.

School-based programs, such as Playworks, that guide students in organized activities during recess and make improvements to the recess play yard may lead to significant increases in physical activity-especially for girls. This study builds on past research by investigating the impact of Playworks separately for girls and boys. Twenty-nine schools were randomly assigned to receive Playworks for 1 school year or serve as a control group. Postintervention physical activity data were collected via accelerometers and recess observations. Impacts were estimated separately for girls and boys using regression models. Girls in Playworks schools had significantly higher accelerometer intensity counts and spent more time in vigorous physical activity than girls in control schools. No significant differences based on accelerometer data were found for boys. A significant impact was also found on the types of activities in which girls engaged during recess; girls in the treatment group were less likely than those in the control group to be sedentary and more likely to engage in jumping, tag, and playground games. The current findings suggest that Playworks had a significant impact on some measures of girls' physical activity, but no significant impact on measures of boys' physical activity.

Recess physical activity and perceived school environment among elementary school children.

Differences in recess physical activity (PA) according to perceived school environment among elementary school children were examined. Participants were 103 children from two schools in Japan. PA was measured using accelerometry for seven consecutive days. Time spent in sedentary or PA (light, moderate, or vigorous) during their morning recess (25 min) and lunch recess (15 min) was determined. The School Physical Activity Environment Scale (three factors: equipment, facility, and safety) was used to investigate perceived school environment. Environmental factor scores were assigned to low or high groups for each factor by median. An analysis of covariance, with grade as the covariate, was conducted separately by gender to examine differences in PA between two groups. During lunch recess, boys in the high-equipment group spent significantly more time in moderate PA (high: 1.5; low: 0.8 min) whereas girls in this group spent less time in light PA (9.3, 11.0). Boys in the high-facility group spent significantly less time in sedentary (2.3, 3.9) and more time in vigorous PA (2.4, 1.4) during lunch recess, and girls spent more time in moderate (2.1, 1.2) and vigorous PA (1.9, 1.3) during morning recess. Differences were observed in recess PA according to school environment perceptions. The present study may be useful for further intervention studies for the promotion of PA during recess.

Impact of a pilot pharmacy health-care professional out-of-school time physical activity and nutrition education program with exercise on fourth and fifth graders in a rural Texas community.

Objectives:Childhood obesity continues to be a problem. Children in rural populations are more likely to be overweight or obese and a lack of resources in those areas may contribute to this problem. We aimed to assess the impact of a pilot pharmacy health-care professional out-of-school time vigorous physical activity and nutrition education program on fourth and fifth graders in a rural Texas community.Methods:We conducted a prospective 12-week cohort study from August to November 2012. Thirty-three children, aged 8–11 years, in Bailey County, Texas, were enrolled in the study. Body mass index, body mass index percentile, blood pressure, waist circumference, and a diet preferences and activities knowledge survey were obtained at 0, 4, 8, and 12 weeks. Study participants completed a twice weekly physical activity and nutrition education program with exercise over weeks 1–4 with no intervention during weeks 5–12.Results:Thirty-one (94%) of the 33 children, predominately Hispanic girls, completed the program. Body mass index (−0.30 (95% confidence interval, −0.44 to −0.17); P = <0.0001), body mass index percentile (−2.75 (95% confidence interval, −4.89 to −0.62); P = 0.0026), systolic blood pressure (−1.9 (95% confidence interval, −2.9 to −0.9); P = <0.0001), and waist circumference (−0.47 (95% confidence interval, −0.85 to −0.10); P = <0.0001) mean change decreased between baseline and week 12 with no intervention for 8 weeks. Positive survey results at 3 months indicated a decrease in fried/sweet foods; increase in exercise; decreases in video games and computer use; and a change in knowledge regarding the selection of the most healthy food group servings per day.Conclusion:In this pharmacy health-care directed pilot study, participants had a reduction of body mass index, body mass index percentile, systolic blood pressure, waist circumference, and improvement in certain survey results at the end of 12 weeks despite no further intervention after 4 weeks.

The Relationship between Stress, Leisure Time Vigorous Physical Activity and Depressive Symptoms in Adolescents

The Relationship between Stress, Leisure Time Vigorous Physical Activity and Depressive Symptoms in Adolescents

Physical Activity, Aerobic Fitness and Body Composition among Students in Malaysia and Libya

The purpose of this study is to compare the physical activity (PA), exercise time and Body Composition, Body Mass Index (BMI), % Body fat (%BF) and aerobic fitness (VO2max) among students in the Faculty of Education UKM Malaysia and Faculty of Education Sabha University Libya (SUL). Respondents drawn from both faculties of education of the two institutions were of average age between 18-25 years. Four-site skinfold thicknesses and Queen’s College Step Test (QCT) were used to determine the percentage body fat (%BF) and aerobic fitness (VO2max) respectively. Physical activity pattern and health status were also assessed by means of the seven days activity of self-reported questionnaire. The study showed a significant difference in terms of moderate (8.59 hrs/wk, 7.48 hrs/wk; t=-3.3, p=.001) and vigorous (4.3 hrs/wk, 6.3 hrs/wk; (t= -7.7, p= .000) time spent in exercising. This also similar with scores for BMI (SUL: m = 22.2; UKM: m = 24.4) and %BF (SUL: m = 13.6%; UKM: m = 16.3%) among students of both SUL (Libya) and UKM (Malaysia). However, analyses revealed that there was no significant difference in VO2max between student-teachers of SUL and UKM (t= -.99, p = .324). This study concludes that participants score an above average of 44 ml.kg -¹ .min -¹ that are considered as being in good fitness and good health. Although SUL students scored lower BMI and less %BF than participants from UKM who reported engaging more time in vigorous physical activity, SUL participants spent significant time in moderate exercises. Lifestyle among student-teachers of UKM Malaysia and SUL Libya did not differ in terms of aerobic fitness but showed significant influence of moderate exercises towards BMI and %BF as for Libyan participants spent more time in moderate activities like walking and gardening.

Validating the multimedia activity recall for children and adolescents in a large New Zealand sample

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

Weekday and weekend patterns of physical activity and sedentary time among Liverpool and Madrid youth

Levels of physical inactivity and sedentary behaviour among English and Spanish youth are high and vary within different regions of each country. Little though is known about these during specific periods of the day. The purpose of this study was to describe physical activity (PA) and sedentary time during segments of the day and week, and compare these critical contexts between youth in the Liverpool and Madrid areas of England and Spain, respectively. PA was objectively assessed in 235 Liverpool- and 241 Madrid youth (aged 10–14 years) who wore accelerometers for seven consecutive days. Minutes of sedentary time, moderate PA, vigorous PA and moderate-to-vigorous physical activity (MVPA) were calculated for weekdays, weekend days, school time, non-school time and after-school. Between-country differences were analysed using analysis of covariance (ANCOVA). Madrid youth spent significantly more time in sedentary activities than their Liverpool counterparts. Madrid youth engaged in more minutes of moderate intensity physical activity (MPA) than Liverpool youth during weekdays, school time and non-school time (P<0.01). Liverpool children recorded more time in vigorous physical activity (VPA) than Madrid peers during week days and weekend days (P<0.01) and during school time and after-school periods (P <0.01). The MVPA was significantly higher among Madrid youth during non-school time (P<0.01). Around 25% of all youth achieved recommended levels of MVPA. Low levels of MVPA and systematic differences in sedentary time, MPA and VPA exist between Liverpool and Madrid youth. Interventions targeted at the least-active children during weekends, after-school and non-school periods within the cultural contexts common to each city are required.

Frequent walking, but not total physical activity, is associated with increased fracture incidence: A 5-year follow-up of an Australian population-based prospective study (AusDiab)

Current public health physical activity (PA) guidelines recommend that older adults accumulate ≥ 2.5 hours per week of moderate- to vigorous-intensity PA to optimize health. The aim of this study was to examine (1) whether adults who meet the current PA guidelines are at reduced risk of fracture, (2) whether fracture risk varies by PA type/intensity and frequency, and (3) whether prolonged TV viewing, as a marker of sedentary behavior, is associated with fracture risk. This national, population-based prospective study with a 5-year follow-up included 2780 postmenopausal women and 2129 men aged 50 years or older. Incident nontraumatic clinical fractures were self-reported. Overall, 307 (6.3%) participants sustained at least one incident low-trauma fracture (women 9.3%, men 2.3%). Multivariate logistic regression, adjusting for age, body mass index (BMI), physical function, previous fracture history, smoking, and dietary calcium and serum 25-hydroxyvitamin D levels, showed that women who walked more than 3 hours per week or completed at least 6 weekly bouts of walking had a 51% and 56% increased fracture risk, respectively, compared with women who did no walking [odds ratio (OR) time = 1.51, 95% confidence interval (CI) 1.01-2.24; OR frequency = 1.56, 95% CI 1.07-2.27]. However, total and moderate to vigorous PA time and the accumulation of 2.5 hours per week or more of PA and TV viewing time were not associated with incident fractures. In men, there also was an increased fracture risk for those who walked more than 3 hours per week (OR = 2.30, 95% CI 1.06-4.97) compared with those who reported no walking. In conclusion, older adults who adhered to the current PA guidelines were not protected against fragility fractures, but more frequent walking was associated with an increased fracture risk.

在宅高齢者における転倒自己効力感に影響を与える因子の検討

Falling is one of the most common health hazards for the elderly. Tinetti et al. (1990) proposed the concept of falls self-efficacy, which explored fear of falling from the perspective of self-efficacy. Falls self-efficacy and its associated factors have not been extensively studied in Japan. This study examined the impact of various factors associated with daily life on falls self-efficacy. We conducted individual interviews with 180 elderly participants (men=93; women=87) on topics such as falls self-efficacy, perceived health status, and time spent on physical activities. Multiple linear regression analysis revealed that the main factors influencing falls self-efficacy were perceived health status, past experience of falling, age, chronic pain, average time spent sitting during a weekday, and moderate or vigorous physical activity time per week. Falls self-efficacy was not significantly associated with gender, human environment, recent falling of acquaintances, or walking time per week. The results indicated that moderate or vigorous physical activity could enhance falls self-efficacy. Moreover, past falling experiences were negatively associated with falls self-efficacy, whereas perceived health status and chronic pain had a significant impact. Future fall prevention programs should adopt a multifactorial approach that focuses on enhancing falls self-efficacy.

PE and Recess Differences in Social Engagement and Physical Activity in Children with Autism

Physical activity (PA) in children with autism can be explained to some extent by the self-determination model (Wehmeyer and Gamer, 2003). This theory operates on an assumption of reciprocity between the individual and the environment. Children with autism may be at risk for inactivity due to social and behavioral deficits often associated with the condition. Yet, children with autism may be more affected by social and environmental constraints than the actual impairment. PURPOSE: To compare physical education (PE) and recess differences of children with autism in social engagement and PA patterns. METHODS: Twenty-six (Asperger, n=6; high-functioning autism, n=12; moderate autism, n=8) children with autism aged 7-12 (9.23±1.45 yrs) participated. Physical activity was measured with a uniaxial accelerometer (Actigraph GT1M), and social engagement was assessed with the Engagement Check (McWilliam, 1990). The accelerometer was worn during school time for 5 consecutive school days, and social engagement was videotaped and observed for one recess period each day and all PE sessions in a week. Physical activity data are reported as percentage of time engaged in moderate-vigorous PA (MVPA), vigorous PA (VPA), and step counts (steps/minute). Social engagement data are reported as percentage of interactive and noninteractive engagements with peers and adults. A Wilcoxon matched pairs signed-rank test was used to examine differences between settings. Significance was set at p<0.05. RESULTS: Findings indicate that (a) children with autism spent significantly more percentage of time in VPA (8.23%±8.98 vs. 2.65%±3.26, Z=3.59, p<0.01) and walked more (3839±1987 vs. 1557±846, Z=3.95, p<0.01) during PE than recess, and (b) percentage of interactive engagement with adults (30.24%±28.24 vs. 12.22%±17.14, Z=3.29, p<0.01) and noninteractive engagement with peers (23.96%±27.54 vs. 9.33%±20.63, Z=2.11, p<0.05) were significantly higher during PE as compared to recess. CONCLUSIONS: The results suggest that children with autism have higher PA and social engagement opportunities during structured PE than recess. Unstructured recess time might be redesigned to provide support and encouragement to be physically active and socially engaged. Supported by grant NSC 95-2413-H-017-010, National Science Council, Taiwan.

Peripheral Bone Mineral Density and Different Intensities of Physical Activity in Children 6–8 Years Old: The Copenhagen School Child Intervention Study

This study aimed to evaluate the association between objectively measured habitual physical activity and calcaneal and forearm bone mineral density (BMD, g/cm(2)), one mechanically more loaded and one less loaded skeletal region, in children aged 6-8 years. BMD was measured in 297 boys and 265 girls by peripheral dual-energy X-ray absorptiometry in the forearm and calcaneus. An accelerometer registered the level of physical activity during 4 days (2 weekdays and the weekend). Weight, height, and skinfold thickness were measured. In order to establish thresholds (count . min(-1)) for bone-stimulating physical activity, we evaluated different definitions of vigorous physical activity. The boys had 3.2% higher distal forearm bone mineral content (BMC, P < 0.001) and 4.5% higher distal forearm BMD (P < 0.001) than the girls. They also carried out 9.7% more daily physical activity and spent 14.6-19.0% more time in vigorous physical activity (all P < 0.05) compared to the girls. In contrast, the girls had 3.8% higher calcaneal BMC (P < 0.01) and 2.5% higher calcaneal BMD (P < 0.05) than the boys. Both calcaneal and forearm BMD were significantly related to total time of daily physical activity as well as with intense physical activity above all the chosen cut-off points (all P < 0.05). The beta value for mean count . min(-1) physical activity was significantly lower than that for all the chosen cut-off points of vigorous activity both for calcaneal and distal forearm BMD. This study suggests that both habitual daily physical activity and amount of vigorous physical activity in children aged 6-8 years are associated with appendicular BMD.

Does Seasonal Changes in Temperature Affect Levels of Vigorous Physical Activity in Preschool-Aged Children?

2062 It has been suggested that when assessing physical activity in young children, seasonal changes be controlled in describing differences. Colder temperatures and less daylight hours in the winter are likely to influence the decision of parents and childcare providers in sending preschool-aged children outdoors. PURPOSE: This study focused on comparing the vigorous physical activity (VPA) levels of preschoolaged children during colder (January-March) and warmer seasons (May-July) in the Midwest region of the United States. It is expected that less time will be spent in VPA during the winter months since it is likely less time will be spent outdoors. METHODS: Subjects included 28 children (12 males, 16 females) age 3–5 (mean age 3.82 ± .55 years) from six childcare centers in northeast Iowa. The cold months averaged −2 degrees C (SD = 5.8) daily high, while the warm months averaged 24 degrees C (SD = 4.9). No difference occurred in precipitation between these seasons. The children were objectively assessed for physical activity using Actwatch-16 activity monitors (Sunriver, OR, USA) for three weekdays during each season. VPA was determined by identifying the number of 15s epoch (time intervals) that the child activity counts > 250. From this procedure, the number total minutes were determined for the day. The three days were averaged to determine total minutes per day, and time in VPA at the center and at home. RESULTS: The mean (SD) minutes spent daily in VPA for the cold and warm months were 67.23 (21.65) and 66.48 (25.29) respectively. A dependent t-test indicated no significant difference in daily VPA between cold and warm months (p = 0.865). In addition, dependent t-tests indicated no significant difference between minutes spent in VPA at the center (p = 0.258) and the home (p = 0.398) when comparing cold versus warm months. There was however a significant (p<0.1) moderate correlation between the locations for the cold (r = 0.59) and warm (r = 0.54) months. CONCLUSIONS: Therefore it is concluded that for the preschool-aged children in this region enrolled in these child-care centers, temperature differences between seasons did not impact the level of VPA