Changes in physical activity patterns in the United States, by sex and cross-sectional age

Social, behavioral, and biological factors, and sex differences in mortality

Few studies have examined whether sex differences in mortality are associated with different distributions of risk factors or result from the unique relationships between risk factors and mortality for men and women. We extend previous research by systematically testing a variety offactors, including health behaviors, social ties, socioeconomic status, and biological indicators of health. We employ the National Health and Nutritional Examination Survey III Linked Mortality File and use Cox proportional hazards models to examine sex diferences in adult mortality in the United States. Our findings document that social and behavioral characteristics are key factors related to the sex gap in mortality. Once we controlfor women's lower levels of marriage, poverty, and exercise, the sex gap in mortality widens; and once we control for women 's greater propensity to visit with friends and relatives, attend religious services, and abstain from smoking, the sex gap in mortality narrows. Biological factors-including indicators of inflammation and cardiovascular risk-also inform sex differences in mortality. Nevertheless, persistent sex differences in mortality remain: compared with women, men have 30% to 83% higher risks of death over the follow-up period, depending on the covariates included in the model. Although the prevalence of risk factors difers by sex, the impact of those risk factors on mortality is similar for men and women.

Physical activity and body mass index of school children and adolescents in Abeokuta, Southwest Nigeria

BACKGROUND

Physical inactivity and sedentary lifestyles are known to predispose to overweight and obesity. These lifestyles are also known to track from childhood into adulthood with consequent cardiovascular and metabolic problems. This study aimed to describe the frequency of physical activity and the relationship between physical activity and body mass index of urban Nigerian school children and adolescents.

METHODS

Children from seven schools in Abeokuta, southwest Nigeria were selected using a multi-staged random sampling technique.

RESULTS

Of 570 children, 411 (72.1%) were involved in moderate to vigorous physical activities. Involvement in physical activity was higher in older children (P<0.001), males (P<0.001), and children of mothers with a higher educational level (P=0.03). Eleven (1.9%) children were overweight or obese whereas 163 (28.6%) were underweight. There were more children with underweight than overweight among the subject population with a high level of physical activity (35.6% vs. 4.4%, P=0.499).

CONCLUSIONS

A large proportion of the children in urban Nigeria participate in physical activity. The prevalence of overweight and obesity is low but undernutrition is a major nutritional problem among these children.

Gender differences in adolescent sport participation, teasing, self-objectification and body image concerns

This study examined gender differences in adolescent participation in sport and physical activity, in teasing experiences specific to the physical activity domain, and the relationship between adolescent physical activity and body image. A sample of 714 adolescents (332 girls, 382 boys) aged between 12 and 16 years completed measures of participation in organised sport and other physical activities, experiences of teasing specific to sport, self-objectification and body image. Adolescent girls participated in organised sport at a lower rate than boys, but experienced higher levels of teasing. Both girls and boys reported being teased by same-sex peers, but in addition, girls also reported being teased by opposite-sex peers (i.e. boys). Time spent on aesthetic physical activities was related to disordered eating symptomatology for both girls and boys. It was concluded that teasing and body image concerns may contribute to adolescent girls' reduced rates of participation in sports and other physical activities.

Predictors of Physical Activity Patterns Across Adulthood: A Growth Curve Analysis

Activity level is a core but understudied individual difference. Understanding patterns of physical activity over long periods may be key to understanding why some individuals develop healthy lifestyles. The present study transformed qualitative information from the Terman Life Cycle Study to examine patterns of leisure time physical activity across four decades (1936-1972). Activities were converted into metabolic equivalent (MET) ratings, and then activity patterns, individual variation, and child and adult personality predictors of differing trajectories were examined using growth curve modeling. For overall activity, a quadratic model fit best, with decelerating decline as people aged. Males were consistently more active than females. Much individual variation was present, but childhood energy and sociability, and adult extraversion and neuroticism predicted average activity levels and change. Results suggest that physical activity needs to be understood within the context of the individual’s personality and long-term trajectory, not merely current motivations.

Patterns of children's participation in unorganized physical activity

Children's leisure-time or unorganized physical activity is associated with positive physical and mental health, yet there is little information available on tracking and predicting participation throughout the childhood and adolescent years. The purpose of the current study was to explore patterns of unorganized physical activity participation of children ages 4 through 17 years. Longitudinal data from the Canadian National Longitudinal Survey of Children and Youth were analyzed using semiparametrice group-based trajectory modeling Participation in unorganized physical activity was best represented by two trajectory groups for boys (n = 4,476) and girls (n = 4,502). For boys, these groups were labeled regular participation and infrequent participation. For girls, there was also a regular group and a second group that reflected infrequent and decreasing participation throughout childhood and adolescence. A higher educational level for parents and having two parents in the home predicted regular participation for boys. For girls, none of the examined variables were significant predictors. The results suggest that boys have a relatively stable pattern of unorganized physical activity throughout childhood and adolescence; however, for some girls, participation declines in adolescence.

Longitudinal physical activity changes in older men in the Osteoporotic Fractures in Men Study

OBJECTIVES

To describe the change in physical activity (total, leisure, household, occupational) in men over a mean 5-year follow-up period and to identify sociodemographic and health factors associated with change in physical activity.

DESIGN

Prospective cohort study; Osteoporotic Fractures in Men Study; data collected March 2000 through May 2006.

SETTING

Six U.S. clinical centers.

PARTICIPANTS

Volunteer sample of ambulatory community-dwelling men aged 65 and older (N=5,161).

MEASUREMENTS

Self-reported physical activity assessed at baseline and Visit 2 (V2) (5 years apart) according to the Physical Activity Scale for the Elderly (PASE) (unitless, relative measure of physical activity).

RESULTS

At baseline, PASE scores averaged 16.8+/-35.5 for occupational, 37.0+/-34.0 for leisure, 95.9+/-43.2 for household, and 149.7+/-67.6 for total physical activity. Occupational (-6.2+/-33.9), leisure (-3.2+/-37.3), household (-9.9+/-44.3), and total (-19.3+/-67.7) physical activity change scores declined, on average, from baseline to V2. On average, change in total PASE scores declined more with age: -15.6+/-71.6 for men younger than 70, -16.4+/-67.0 for men aged 70 to 74, -21.4+/-66.9 for men aged 75 to 79, and -29.5+/-60.7 for men aged 80 and older. Living alone, smoking cigarettes, poor health, and higher blood pressure were associated with greater declines in physical activity over time. Although average scores declined, some older men (1,335, 26%) reported increasing physical activity levels. Better physical and mental health, living with others, and being younger were associated with the probability of increasing physical activity over time.

CONCLUSION

Over the 5-year period, the majority of men reported declines in total physical activity. Older men in poor health who live alone have a high risk of physical activity declines and may be an important group to target for exercise interventions.

Parent and child physical activity and sedentary time: do active parents foster active children?

Background

Physical activity has many positive effects on children's health while TV viewing has been associated with adverse health outcomes. Many children do not meet physical activity recommendations and exceed TV viewing guidelines. Parents are likely to be an important influence on their children's behaviour. There is an absence of information about the associations between parents' and children's physical activity and TV viewing.

Methods

Year 6 children and their parent were recruited from 40 primary schools. Results are presented for the 340 parent-child dyads with accelerometer data that met a ≥ 3 day inclusion criteria and the 431 parent-child dyads with complete self-reported TV viewing. Over 80% of the dyads with valid TV viewing data included mothers and their child. Mean minutes of moderate to vigorous physical activity (MVPA), minutes of sedentary time per day and counts per minute were assessed by accelerometer. Self-reported hours of TV viewing were coded into 3 groups (< 2 hours per day, 2-4 hours per day and >4 hours per day. Linear and multi-nominal regression models were run by child gender to examine parent-child associations.

Results

In linear regression models there was an association for the overall sedentary time of girls and their parents (t = 2.04. p = .020) but there was no association between girls' and parents' physical activity. There were no associations between parents' and boys' sedentary or physical activity time. For girls, the risk of watching more than 4 hours of TV per day, (reference = 2 hours of TV per day), was 3.67 times higher if the girl's parent watched 2-4 hours of TV per day (p = 0.037). For boys, the risk of watching more than 4 hours of TV per day, was 10.47 times higher if the boy's parent watched more than 4 hours of TV per day (p = 0.038).

Conclusions

There are associations in the sedentary time of parents and daughters. Higher parental TV viewing was associated with an increased risk of high levels of TV viewing for both boys and girls. There were no associations between the time that parents and children spend engaged in physical activity.

Quality of diet and potential renal acid load as risk factors for reduced bone density in elderly women

BACKGROUND

Bone mineral density (BMD) may be influenced by the general dietary pattern and the potential renal acid load (PRAL).

METHODS

We compared the dietary intake (estimated using the European Prospective Investigation into Cancer and nutrition questionnaire) of 497 community-living women (60 years of age and older) grouped according to tertiles of baseline total, trabecular and cortical BMD estimated using tibial peripheral quantitative computed tomography (pQCT), and of BMD variation over 6 years.

RESULTS

None of the nutrients taken into account nor PRAL was associated with total BMD, with the exception that the intake of polyunsaturated fatty acids (PUFA) was slightly higher among women with the highest total BMD. Similar results were found for trabecular BMD. Cortical BMD was associated with serum 25-OH vitamin D (38.8, 43.2, and 49.5 nmol/L in the first, second, and third tertiles, respectively; P=0.042). In the longitudinal analysis, a lower BMI was associated with greater loss of total BMD, while lower serum 25-OH vitamin D at baseline was associated with smaller loss of cortical BMD.

CONCLUSIONS

We found no relationship between dietary acid load and BMD. We also confirmed the role of well-recognized risk factor for osteoporosis.

Physical activity in survivors of childhood acute lymphoblastic leukaemia

AIM

To objectively measure levels of physical activity in children, following treatment for acute lymphoblastic leukaemia (ALL).

METHODS

Nineteen children who had completed treatment for ALL 6 months-5 years prior to study enrollment wore an accelerometer for 2 weekdays and 2 weekend days.

RESULTS

The children spent an average of 141 +/- 74 min/day engaged in moderate to vigorous physical activity (MVPA), an amount similar to that previously documented in healthy children. Only three of the 19 subjects averaged less MVPA than the recommended amount (at least 60 min/day). MVPA levels were significantly higher on weekdays than weekend days (P= 0.006). Overall, boys engaged in significantly more MVPA than girls (P= 0.029). MVPA time was negatively correlated with age (r =-0.80) and age at diagnosis (r =-0.87). No trend between MVPA and time off treatment or body mass index was identified.

CONCLUSIONS

Survivors of childhood ALL appear to be engaging in similar amounts of MVPA as those of the healthy children and are meeting recommended levels of physical activity.

Social-cognitive correlates of physical activity in a multi-ethnic cohort of middle-school girls: two-year prospective study

OBJECTIVE

The study examined social-cognitive correlates of physical activity in a multi-ethnic cohort of girls from six regions of the United States who participated in the Trial of Activity for Adolescent Girls during their 6th and 8th grade school years.

METHODS

Girls completed validated questionnaires and wore accelerometers that measured weekly physical activity in the spring of 2002 and 2005.

RESULTS

In 8th grade, self-efficacy and perceived social support had indirect relations with physical activity mediated through perceived barriers, which was inversely related to physical activity. Self-efficacy also had a direct relation with physical activity.

CONCLUSIONS

Correlations were smaller than those obtained in studies that measured physical activity by self-reports, suggesting that previous estimates were inflated by common method artifact. Nonetheless, physical activity trials among girls during early adolescence might focus on increasing self-efficacy for overcoming barriers to physical activity and on ways by which perceived barriers can otherwise be reduced.

Physical activity resources and changes in walking in a cohort of older men

OBJECTIVES

We evaluated the influence of physical activity resources and neighborhood-level socioeconomic status (SES) on walking among community-dwelling older men.

METHODS

Participants reported time walked per day at baseline (2000-2002) and follow-up. Residential addresses were linked to a geographic information system database to assess proximity to parks, trails, and recreational facilities. Log-binomial regression analyses were conducted to test the hypothesis that men living near physical activity resources were more likely to increase or maintain time walked.

RESULTS

Average time walked per day declined by 6 minutes between baseline and follow-up (P < .05). There was a significant interaction of neighborhood SES and physical activity with walking time (P < .1). Proximity to parks and proximity to trails, respectively, were associated with a 22% (95% confidence interval [CI] = 1.01, 1.47) and 34% (95% CI = 1.16, 1.55) higher likelihood of maintaining or increasing walking time in high-SES neighborhoods, but there was no association in low-SES neighborhoods. Proximity to recreational facilities was not associated with walking.

CONCLUSIONS

Uncovering reasons that proximity to parks and trails is not associated with maintenance of walking activity among men in low-SES neighborhoods could provide new insight into ways to promote physical activity.

Changes in leisure-time physical activity and sedentary behaviour at retirement: a prospective study in middle-aged French subjects

BACKGROUND

Longitudinal studies on physical activity patterns around retirement age are scarce and provide divergent findings. Little is known about changes in sedentary behaviour in this context. Our aim was to investigate relationships between retirement and 3-year changes in leisure-time physical activity (LTPA) patterns and sedentary behaviour in middle-aged French adults.

METHODS

Past-year LTPA and sedentary behaviour (watching television) were assessed in 1998 and 2001 using the Modifiable Activity Questionnaire on participants in the SU.VI.MAX (Supplementation with Antioxidants and Minerals) study. A total of 698 men and 691 women aged 45-64 were included in this analysis. Comparisons were made between subjects who had retired between 1998 and 2001 and those who continued to work, using the Chi-square test, Student t-test, Wilcoxon rank test or covariance analysis where appropriate.

RESULTS

20.1% of men and 15.6% of women retired during follow-up. The baseline LTPA level was similar between subjects who retired during follow-up and those who continued to work. Mean LTPA increased by about 2 h/week in men and women who had retired, whereas no change was observed in employed persons. The positive change in LTPA following retirement was mainly related to an increase in activities of moderate intensity, such as walking. Retirement did not modify the ranking of the most frequently performed LTPAs, but the number of participants and the duration increased through retirement. In men, the increase in time spent watching TV was more than twice as high in retirees as in workers (+40.5 vs. +15.0 min/day, P < 0.0001). The same tendency was observed among women, but was borderline non-significant (+33.5 vs. +19.9 min/day, P = 0.05). In women, retirees who increased their walking duration by 2 h/week or more also decreased time spent watching TV by 11.5 min/day.

CONCLUSIONS

Retirement was associated with both an increase in LTPAs and in time spent watching TV, suggesting that retirement is an important period not only for promoting physical activity, but also for limiting sedentary behaviour.

Physical activity correlates in young women with depressive symptoms: a qualitative study

Background

Young women are at high risk for developing depression and participation in physical activity may prevent or treat the disorder. However, the influences on physical activity behaviors of young women with depression are not well understood. The aim of this study was to gather in-depth information about the correlates of physical activity among young women with and without depressive symptoms.

Methods

A sample of 40 young women (aged 18-30 years), 20 with depressive symptoms (assessed using the CES-D 10) and 20 without depressive symptoms participated in one-on-one semi-structured interviews. A social-ecological framework was used, focusing on the individual, social and physical environmental influences on physical activity. Thematic analyses were performed on transcribed interview data.

Results

The results indicated several key themes that were unique to women with depressive symptoms. These women more often described negative physical activity experiences during their youth, more barriers to physical activity, participating in more spontaneous than planned activity, lower self-efficacy for physical activity and being influenced by their friends' and family's inactivity.

Conclusions

Interventions designed to promote physical activity in this important target group should consider strategies to reduce/overcome early life negative experiences, engage support from family and friends and plan for activity in advance.

Physical activity behaviors of students of a rural historically black college

Physical activity can have a positive impact on health disparities among African Americans.

OBJECTIVE

In this study, we assessed physical activity behaviors and correlates of students of a Historically Black College.

METHODS

In September 2004, an online survey and pedometers were used to measure physical activity behavior and correlates.

PARTICIPANTS

A convenience sample of 106 students completed the survey and received pedometers. Pedometer data were submitted online for 5 weeks.

RESULTS

One hundred and six students completed the survey. Twenty-eight percent and 41% of respondents met recommendations for moderate physical activity and vigorous physical activity, respectively. Week 1 daily pedometer step count average was 8,707. Most students reported positive outcome expectations for physical activity. Students submitting pedometer data were less likely to meet MPA recommendations than students only completing the survey.

CONCLUSIONS

African American students feel positive about physical activity yet most do not meet recommended levels.

Rural and urban park visits and park-based physical activity

OBJECTIVE

A physical activity disparity exists between rural and urban residents. Community parks are resources for physical activity because they are publicly provided, available at a low cost, and accessible to most residents. We examine the use of and physical activity outcomes associated with rural and urban parks.

METHODS

Onsite observations were conducted using the System for Observing Play and Recreation in Communities (SOPARC) at four rural and four urban parks. Momentary sampling scans were conducted four times per day for seven days at each site.

RESULTS

A total of 6,545 park visitors were observed. Both rural and urban park visitors were observed more often at larger parks with paved trails and attended most often on weekends. Rural park visits were more frequent than urban park visits but rural visits were less physically active.

CONCLUSION

Although similarities were observed between rural and urban park visits, differences suggest that findings from park and physical activity studies in urban areas should not be considered representative of their rural counterparts. Given that the majority of existing park and physical activity research has been undertaken in urban settings, the need for complementary research in rural settings has been made evident through this presentation of baseline descriptive data.

Energy expenditure and aging

The study of energy expenditure (EE) has deep roots in understanding aging and lifespan in all species. In humans, total EE decreases substantially in advanced age resulting from parallel changes in resting metabolic rate (RMR) and activity EE. For RMR, this reduction appears to be due to a reduction in organ mass and specific metabolic rates of individual tissues. However, these anatomical changes explain very little regarding the decline in activity EE, which is governed by both genetic and environmental sources. The biological control centers for activity EE are closely coupled with body mass fluctuations and seem to originate in the brain. Several candidate neuromodulators may be involved in the age-related reduction of activity EE that include: orexin, agouti-related proteins and dopaminergic pathways. Unfortunately, the existing body of research has primarily focused on how neuromodulators influence weight gain and only a few studies have been performed in aging models. Recent evidence suggests that activity EE has an important role in dictating lifespan and thus places emphasis on future research to uncover the underlying biological mechanisms. The study of EE continues to unlock clues to aging.

Description of exercise participation of adolescents with cerebral palsy across a 4-year period

PURPOSE

The purposes of this study were to describe (1) the types of exercise participation of adolescents with cerebral palsy; (2) the weekly duration of stretching, strengthening, and cardiovascular exercise; (3) how the level of activity compares with national health guidelines; and (4) the change in participation over 4 years.

METHODS

Participants included 126 males and 104 females (mean age = 14.7 years, SD = 1.7 years) who reported physical activities in the previous week. Analyses included frequency counts and proportions, stacked bar graphs, and 2-way analyses of variance of exercise participation by Gross Motor Function Classification System (GMFCS) and sex.

RESULTS

A significant main effect of GMFCS level was detected for light and moderate exercise. A significant interaction of GMFCS level and sex was found for stretching; females stretched more. An average of 9.4% and 11.4% of our sample participated in weekly levels of moderate and vigorous exercise, respectively.

CONCLUSIONS

Pediatric physical therapists should promote increased exercise participation rates among youths with cerebral palsy.

Associations of residential density with adolescents' physical activity in a rapidly urbanizing area of Mainland China

In the context of recent social and economic transitions in China, lack of physical activity among adolescents is an emerging health risk, particularly so in rapidly expanding urban areas. Evidence from Western countries suggests that built environment attributes can influence the physical activity participation of young people, but whether or not this is the case for China is unknown. We recruited high school students from ten urban districts in Nanjing, Mainland China (n = 2,375; mean age = 13.9 +/- 1.0 years old; 46% boys; survey response rate = 89%). The outcome variable was self-reported recreational physical activity time; the primary explanatory variable was the residential density of the urban districts. Analysis was conducted using mixed-effects logistic regression models. After adjustment for potential confounding variables, including sedentary behavior and green space, there was a consistent and graduated association between residential density and physical activity; residential density was significantly negatively associated with recreational physical activity time for students from the higher tertile of residential density (OR; 95% CI = 0.64; 0.42 to 0.97) compared to those from the lower tertile. The direction and magnitude of the negative association between residential density and physical activity was similar for boys and girls. It should be a public health priority to identify the particular urban environment attributes that can encourage and support young people's participation in physical activity.

Validity of social-cognitive measures for physical activity in middle-school girls

OBJECTIVE

The factorial validity and measurement equivalence/invariance of scales used to measure social-cognitive correlates of physical activity among adolescent girls were examined.

METHODS

Confirmatory factor analysis was applied to questionnaire responses obtained from a multi-ethnic sample (N = 4885) of middle-school girls from six regions of the United States. A cohort of 1893 girls completed the scales in both sixth and eighth grades, allowing longitudinal analysis.

RESULTS

Theoretically and statistically sound models were developed for each scale, supporting the factorial validity of the scales in all groups. Multi-group and longitudinal invariance was confirmed across race/ethnicity groups, age within grade, BMI categories, and the 2-year period between grades.

CONCLUSIONS

The scores from the scales provide valid assessments of social-cognitive variables that are putative mediators or moderators of change in physical activity. The revised scales can be used in observational studies of change or interventions designed to increase physical activity among girls during early adolescence.

Mediators affecting girls' levels of physical activity outside of school: findings from the trial of activity in adolescent girls

BACKGROUND

Providing after school activities is a community level approach for reducing the decline in physical activity of girls as they reach early adolescence.

PURPOSE

The purpose of this study was to examine psychosocial, environmental, and behavioral factors as potential mediators of after school physical activity in adolescent girls.

METHODS

We assessed objectively measured levels of physical activity occurring outside of school and potential predictors and mediators of activity in girls participating in the Trial of Activity in Adolescent Girls (TAAG).

RESULTS

We found that the TAAG intervention had a statistically significant and positive effect on out of school activity in the 2006 cohort. Self-efficacy, friends' social support, total social support, and difficulty getting to and from community activities mediated the level of moderate to vigorous physical activity in girls.

CONCLUSIONS

Parents, communities, and schools should provide and enhance opportunities outside of the school day for adolescents to be active. Reducing transportation barriers and enlisting social support appear to be key.

Physical activity and risk of ischemic stroke in the Northern Manhattan Study

BACKGROUND

It is controversial whether physical activity is protective against first stroke among older persons. We sought to examine whether physical activity, as measured by intensity of exercise and energy expended, is protective against ischemic stroke.

METHODS

The Northern Manhattan Study is a prospective cohort study in older, urban-dwelling, multiethnic, stroke-free individuals. Baseline measures of leisure-time physical activity were collected via in-person questionnaires. Cox proportional hazards models were constructed to examine whether energy expended and intensity of physical activity were associated with the risk of incident ischemic stroke.

RESULTS

Physical inactivity was present in 40.5% of the cohort. Over a median follow-up of 9.1 years, there were 238 incident ischemic strokes. Moderate- to heavy-intensity physical activity was associated with a lower risk of ischemic stroke (adjusted hazard ratio [HR] 0.65, 95% confidence interval [0.44-0.98]). Engaging in any physical activity vs none (adjusted HR 1.16, 95% CI 0.88-1.51) and energy expended in kcal/wk (adjusted HR per 500-unit increase 1.01, 95% CI 0.99-1.03) were not associated with ischemic stroke risk. There was an interaction of sex with intensity of physical activity (p = 0.04), such that moderate to heavy activity was protective against ischemic stroke in men (adjusted HR 0.37, 95% CI 0.18-0.78), but not in women (adjusted HR 0.92, 95% CI 0.57-1.50).

CONCLUSIONS

Moderate- to heavy-intensity physical activity, but not energy expended, is protective against risk of ischemic stroke independent of other stroke risk factors in men in our cohort. Engaging in moderate to heavy physical activities may be an important component of primary prevention strategies aimed at reducing stroke risk.

Purposeful exercise and lifestyle physical activity in the lives of young adult women: findings from a diary study

It is important to know how physical activity is incorporated in women's lives to assess ways they can feasibly attain and maintain lifelong healthy practices. This study aimed to determine whether patterns of activity differed among young women whose physical activity met nationally recommended levels from those who did not. The sample was 42 women (aged 18-30 years) who had completed an exercise intervention (22 from the exercise group, 20 from the control group). Participants recorded pedometer steps and physical activities in diaries including form, duration and perceived exertion during 12 randomly assigned weeks over 26 weeks. We divided the sample into quartiles of moderate to vigorous physical activity to examine the composition of physical activities per quartile. Walking and shopping comprised the majority of physical activity in the lowest quartile of moderate to vigorous physical activity. In the second and third quartiles, walking and household/childcare together comprised more than two-thirds of all activities. Only in the highest quartile was cardio activity (not including walking, shopping and household/childcare) the largest proportion of activity; this category stood alone as varying significantly across quartiles of moderate to vigorous physical activity (p < 0.005). Among these young adult women, self-reported "lifestyle" physical activity was not sufficient to meet recommended levels of moderate to vigorous physical activity. The one-quarter who met recommended levels of moderate to vigorous physical activity did so largely through purposeful physical activities directly associated with exercise. Further research is needed to refine means of more fully measuring physical activities that women frequently perform, with particular attention to household work, childcare and shopping and to differing combinations of activities and levels of exertion by which diverse women can meet the recommended levels. The findings of this small scale study reinforce the ongoing benefit of recommending structured, planned physical activity at moderate and vigorous levels of intensity to young, healthy women to ensure they obtain the health benefits.

Neighborhood environment in studies of health of older adults: a systematic review

CONTEXT

Epidemiologists and public health researchers are studying neighborhood's effect on individual health. The health of older adults may be more influenced by their neighborhoods as a result of decreased mobility. However, research on neighborhood's influence on older adults' health, specifically, is limited.

EVIDENCE ACQUISITION

Recent studies on neighborhood and health for older adults were identified. Studies were identified through searches of databases including PsycINFO, CINAHL, PubMed, Academic Search Premier, Ageline, Social Science Citation Index, and Health Source. Criteria for inclusion were as follows: human studies; English language; study sample included adults aged > or =55 years; health outcomes, including mental health, health behaviors, morbidity, and mortality; neighborhood as the primary exposure variable of interest; empirical research; and studies that included > or =10 neighborhoods. Air pollution studies were excluded. Five hundred thirty-eight relevant articles were published during 1997-2007; a total of 33 of these articles met inclusion criteria.

EVIDENCE SYNTHESIS

The measures of objective and perceived aspects of neighborhood were summarized. Neighborhood was primarily operationalized using census-defined boundaries. Measures of neighborhood were principally derived from objective sources of data; eight studies assessed perceived neighborhood alone or in combination with objective measures. Six categories of neighborhood characteristics were socioeconomic composition, racial composition, demographics, perceived resources and/or problems, physical environment, and social environment. The studies are primarily cross-sectional and use administrative data to characterize neighborhood.

CONCLUSIONS

These studies suggest that neighborhood environment is important for older adults' health and functioning.

A walk (or cycle) to the park: active transit to neighborhood amenities, the CARDIA study

BACKGROUND

Building on known associations between active commuting and reduced cardiovascular disease (CVD) risk, this study examines active transit to neighborhood amenities and differences between walking and cycling for transportation.

METHODS

Year-20 data from the Coronary Artery Risk Development in Young Adults study (3549 black and white adults aged 38-50 years in 2005-2006) were analyzed in 2008-2009. Sociodemographic correlates of transportation mode (car-only, walk-only, any cycling, other) to neighborhood amenities were examined in multivariable multinomial logistic models. Gender-stratified multivariable linear or multinomial regression models compared CVD risk factors across transit modes.

RESULTS

Active transit was most common to parks and public transit stops; walking was more common than cycling. Among those who used each amenity, active transit (walk-only and any cycling versus car-only transit) was more common in men and those with no live-in partner and less than full-time employment (significant ORs [95% CI] ranging from 1.56 [1.08, 2.27] to 4.54 [1.70, 12.14]), and less common in those with children. Active transit to any neighborhood amenity was associated with more favorable BMI, waist circumference, and fitness (largest coefficient [95% CI] -1.68 [-2.81, -0.55] for BMI, -3.41 [-5.71, -1.11] for waist circumference [cm], and 36.65 [17.99, 55.31] for treadmill test duration [seconds]). Only cycling was associated with lower lifetime CVD risk classification.

CONCLUSIONS

Active transit to neighborhood amenities was related to sociodemographics and CVD risk factors. Variation in health-related benefits by active transit mode, if validated in prospective studies, may have implications for transportation planning and research.

Physical activity and successful aging in Canadian older adults

Rowe and Kahn (1987) proposed that successful aging is the balance of three components: absence of disease and disease-related disability, high functional capacity, and active engagement with life. This study examines the relationship between physical activity involvement and successful aging in Canadian older adults using data from the Canadian Community Health Survey, cycle 2.1 (N = 12,042). Eleven percent of Canadian older adults were aging successfully, 77.6% were moderately successful, and 11.4% were unsuccessful according to Rowe and Kahn's criteria. Results indicate that physically active respondents were more than twice as likely to be rated as aging successfully, even after removing variance associated with demographic covariates. These findings provide valuable information for researchers and practitioners interested in age-specific interventions to improve older individuals' likelihood of aging successfully.

Regional brain activation and affective response to physical activity among healthy adolescents

Research has shown that frontal brain activation, assessed via electroencephalographic (EEG) asymmetry, predicts the post-exercise affective response to exercise among adults. Building on this evidence, the present study investigates the utility of resting cortical asymmetry for explaining variance in the affective response both during and after exercise at two different intensities among healthy adolescents. Resting EEG was obtained from 98 adolescents (55% male), who also completed two 30-min exercise tasks on a cycle ergometer at a moderate and hard intensity. Affect (as measured by the Feeling Scale) was assessed prior to exercise, every 10min during exercise, immediately post-exercise, and 10min post-exercise. When moderate exercise was performed first, resting frontal cortical asymmetry was related to the affective response to moderate exercise, such that left-dominant adolescents reported more positive affect compared to right-dominant adolescents. When hard exercise was performed first, the association was not significant. The results are interpreted in light of current theory related to affect in response to exercise.

Steps per day: the road to senior health?

In older adults, as in younger individuals, habitual moderate-intensity physical activity is associated with a reduced risk of various chronic health conditions, including certain types of cardiovascular and musculoskeletal disease and certain forms of cancer. However, the pattern of physical activity associated with such benefits remains unclear. One problem is that most investigators have examined patterns of physical activity using either subjective questionnaires or accelerometer or pedometer measurements limited to a single week, despite clear evidence of both the unreliability/invalidity of questionnaires and seasonal changes in activity patterns. Since 2000, we have thus conducted an interdisciplinary study examining the habitual physical activity and health of elderly people living in a medium-sized Japanese town (the Nakanojo Study). In about one-tenth of some 5000 available subjects aged > or =65 years, physical activity has already been assessed continuously for 24 h/day for >8 years using a specially adapted pedometer/accelerometer. This device has a storage capacity of 36 days and can distinguish >10 intensities of physical activity (expressed in metabolic equivalents [METs]). Data have to date been summarized as daily step counts and daily durations of activity of <3 and >3 METs, averaged over a 1-year period. This article provides a detailed overview of both factors influencing habitual physical activity and relationships between such activity and health in an elderly population. To date, analyses have been cross-sectional in type. Substantial associations have been noted between the overall health of participants and both the daily duration of effort undertaken at an intensity of >3 METs and the daily step count. In men, the extent of health is associated more closely with the daily duration of activity of >3 METs than with the daily step count, whereas in women, the association is closer for the step count than for the duration of activity >3 METs. In both sexes, the threshold amount of physical activity associated with better health is greater for physical than for mental benefits: >8000 versus >4000 steps/day and/or >20 versus >5 min/day at an intensity >3 METs, respectively. In other words, better physical health is seen in those spending at least 20 min/day in moderate walking (at a pace of around 1.4 m/s [5 km/h]) and a further >60 min of light activity per day. In contrast, better mental health is associated with much smaller amounts of deliberate physical activity. The daily step count and the daily durations of activity of <3 and >3 METs are all influenced by meteorological factors, particularly precipitation and mean ambient temperature. Activity decreases exponentially to about 4000 steps/day as precipitation increases. Excluding the influence of rainfall, the daily step count peaks at a mean outdoor temperature of around 17 degrees C; above and especially below such readings, physical activity decreases as a quadratic function of temperature. Seasonal changes in microclimate should thus be considered when designing interventions intended to increase the habitual physical activity of elderly people. The observed associations between physical activity and health outcomes point to a need for longitudinal analyses; these should examine potential causal interpretations of the current findings and elucidate possible additional mediating variables.

Overweight and diabetes prevalence among US immigrants

OBJECTIVES

We estimated the prevalence of overweight and diabetes among US immigrants by region of birth.

METHODS

We analyzed data on 34 456 US immigrant adults from the National Health Interview Survey, pooling years 1997 to 2005. We estimated age- and gender-adjusted and multivariable-adjusted overweight and diabetes prevalence by region of birth using logistic regression.

RESULTS

Both men (odds ratio [OR] = 3.3; 95% confidence interval [CI] = 1.9, 5.8) and women (OR = 4.2; 95% CI = 2.3, 7.7) from the Indian subcontinent were more likely than were European migrants to have diabetes without corresponding increased risk of being overweight. Men and women from Mexico, Central America, or the Caribbean were more likely to be overweight (men: OR = 1.5; 95% CI = 1.3, 1.7; women: OR = 2.0; 95% CI = 1.7, 2.2) and to have diabetes (men: OR = 2.0; 95% CI = 1.4, 2.9; women: OR = 2.0; 95% CI = 1.4, 2.8) than were European migrants.

CONCLUSIONS

Considerable heterogeneity in both prevalence of overweight and diabetes by region of birth highlights the importance of making this distinction among US immigrants to better identify subgroups with higher risks of these conditions.

Personality, physical fitness, and affective response to exercise among adolescents

PURPOSE

Evidence shows that aspects of personality are associated with participation in physical activity. We hypothesized that, among adolescents, behavioral activation (BAS) and behavioral inhibition (BIS) systems would be associated with physical fitness (cardiovascular fitness and percent body fat), enjoyment of exercise, tolerance of and persistence in high-intensity exercise, and affective response to an acute exercise bout.

METHODS

One hundred and forty-six healthy adolescents completed a cardiovascular fitness test, percent body fat assessment (dual-energy x-ray absorptiometer), and two 30-min cycle ergometer exercise tasks at moderate and hard intensities. Questionnaires evaluated BIS/BAS, enjoyment of exercise, and preference and tolerance for high-intensity activity. Affect in response to exercise was assessed using the Feeling Scale (FS) and the Activation Deactivation Adjective Check List (AD ACL).

RESULTS

BIS was negatively correlated with cardiovascular fitness and tolerance for high-intensity exercise, and adolescents with high BIS scores reported more negative FS in response to exercise at both moderate and hard intensities. BAS was positively correlated with enjoyment of exercise, and adolescents with high BAS scores reported having more positive FS and higher energetic arousal on the AD ACL in response to moderate-intensity exercise. The association between BAS and affect was attenuated for the hard-intensity exercise task.

CONCLUSION

These findings suggest that both the drive to avoid punishing stimuli (BIS) and the drive to approach rewarding stimuli (BAS) are related to the affective response to exercise. The BIS may be more strongly associated with fitness-related exercise behavior among adolescents than the BAS, whereas the BAS may play a relatively greater role in terms of subjective exercise enjoyment.

Leisure-time physical activity and secondary conditions in women with physical disabilities

PURPOSE

To examine the relationship between secondary conditions and leisure-time physical activity participation (LTPA) in women with physical disabilities.

METHOD

A survey was conducted in a metropolitan urban USA area of women (n=170) with physical disabilities including MS, CP, polio, arthritis, TBI, and CVA among others and aged 21-65 years. Outcome measures were LTPA, secondary conditions (numbers and severity), and functional status.

RESULTS

Respondents experienced 11.99 (+/-6.05) secondary conditions in the past year, self-rated their severity as 'moderate problems', and reported moderate levels of functional impairment. LTPA participation (excluding calisthenics/exercise) was reported to be 2.90 (+/-5.12) times/week with 39.4% reporting no participation. After controlling for the interaction between severity of secondary conditions and functional status, the secondary conditions of physical deconditioning and isolation were significantly and inversely related to LTPA participation (r=-0.164, p=0.036; r=-0.156, p=0.045, respectively).

CONCLUSION

Reported secondary conditions of physical deconditioning and isolation are inversely related to the ability of moderately impaired women with physical disabilities to participate in LTPA when functional status was controlled and should be considered in efforts to increase involvement in this health promoting behaviour.

Association between habitual physical activity and parameters of physical fitness in postmenopausal women

OBJECTIVE

To evaluate the association between physical activity and the morphological, functional and physiological components of physical fitness in postmenopausal women.

METHODS

A cross-sectional study of 162 postmenopausal women, 40-65 years of age, who verbally responded to the International Physical Activity Questionnaire applied to evaluate their level of physical activity. Physical fitness was evaluated by measuring body mass index, waist circumference, body fat percentage, maximum oxygen consumption, plasma levels of total and fractional cholesterol, triglycerides and fasting glucose, as well as blood pressure.

RESULTS

Approximately 83.5% of the women were active, principal physical activities being household chores and transportation walking. Approximately 80% of the women were overweight or obese and presented a waist circumference indicative of high or very high risk for cardiovascular disease, and fat percentage above 33%. Over 50% were found to have low oxygen consumption. There were no significant differences between the groups of active and inactive women with respect to mean body mass index (p = 0.43), percentage of body fat (p = 0.60), hip-to-waist ratio (p = 0.93), waist circumference (p = 0.44), maximum VO2 (p = 0.32), total cholesterol (p = 0.43), fasting glucose (p = 0.73), and systolic (p = 0.79) or diastolic blood pressure (p = 0.48). Adjusted prevalence ratios also showed no significant differences between the groups.

CONCLUSIONS

Habitual physical activity is not associated with variations in the components that are used to describe physical fitness. It is important to encourage physical activity and provide guidelines to ensure that it is carried out in the quantity, duration and intensity required for improving physical fitness level and obtaining health benefits.

Physical activity pattern of prepubescent Filipino school children during school days

BACKGROUND

Little is known about pre-pubescent Filipino children's involvement in moderate-to-vigorous physical activity (MVPA). There are international guidelines regarding required levels of MVPA for healthy children.

METHODS

This study describes participation of 11- to 12-year-olds in randomly selected public and private schools in San Juan, Metromanila, in MVPA and sports during a school day. The Filipino-modified Physical Activity Questionnaire for Older Children (F_PAQ_C) was administered in English and Filipino. Additional data was collected on sex, age, type of school, and amount of time spent using television and computers. Children's self-assessment of physical activities (1 question in the F_PAQ_C) was correlated with their cumulative F_PAQ_C score.

RESULTS

Three hundred eighty subjects (167 boys, 213 girls) participated. Participation in MVPA varied between sex and age groups, from 56.1% to 65.0%. Fewer than 10% of participants were very active. The children were more active during physical education classes than at recess or lunch, after class, or in the evening. Walking for exercise, jumping, jogging and running, free play, and dance were most common. Boys, younger children, and private school students most commonly engaged in MVPA. Self-assessed physical activity had modest correlation (r(2)= 0.21) with cumulative F_PAQ_C score, after adjusting for sex, age, and school type.

CONCLUSION

Most children were not physically active during the school day, except in physical education classes. To reduce the gap between recommended and current activity levels, more opportunities should be provided for preteen Filipino children to engage in MVPA during and after school.

Association of 20-year changes in cardiorespiratory fitness with incident type 2 diabetes: the coronary artery risk development in young adults (CARDIA) fitness study

OBJECTIVE

To test the association of fitness changes over 7 and 20 years on the development of diabetes in middle age.

RESEARCH DESIGN AND METHODS

Fitness was determined based on the duration of a maximal graded exercise treadmill test (Balke protocol) at up to three examinations over 20 years from 3,989 black and white men and women from the Coronary Artery Risk Development in Young Adults study. Relative fitness change (percent) was calculated as the difference between baseline and follow-up treadmill duration/baseline treadmill duration. Diabetes was identified as fasting glucose >or=126 mg/dl, postload glucose >or=200 mg/dl, or use of diabetes medications.

RESULTS

Diabetes developed at a rate of 4 per 1,000 person-years in women (n = 149) and men (n = 122), and lower baseline fitness was associated with a higher incidence of diabetes in all race-sex groups (hazard ratios [HRs] from 1.8 to 2.3). On average, fitness declined 7.6% in women and 9.2% in men over 7 years. The likelihood of developing diabetes increased per SD decrease (19%) from the 7-year population mean change (-8.3%) in women (HR 1.22 [95% CI 1.09-1.39]) and men (1.45 [1.20-1.75]) after adjustment for age, race, smoking, family history of diabetes, baseline fitness, BMI, and fasting glucose. Participants who developed diabetes over 20 years experienced significantly larger declines in relative fitness over 20 years versus those who did not.

CONCLUSIONS

Low fitness is significantly associated with diabetes incidence and explained in large part by the relationship between fitness and BMI.

Latent growth curve modeling of adolescent physical activity: testing parallel process and mediation models

Data from a randomized clinical trial were used to examine the extent to which a health promotion intervention affected changes in psychosocial constructs and if so whether these in turn explained changes in physical activity (PA). PA and psychosocial data on 878 adolescents (ages 11-15) recruited through primary care providers (age M = 12.7 years, SD = 1.3; 58% white non-Hispanic) were measured at baseline, six and 12 months. Parallel process latent growth curve analyses found positive relationships between the growth trajectories of behavior change strategies, self-efficacy, family support, peer support and the growth trajectory of PA. However, mediation analyses did not reveal statistically significant intervention-mediated effects.

Clinical use of physical activity measures

PURPOSE

To provide a review of physical activity measures and subjective and objective methods of its measurement. Considerations for the use of these measurements in research and practice will be discussed.

DATA SOURCES

The PubMed, CINAHL, and Health and Psychosocial Instruments databases, and the Centers for Disease Control Web site were searched using the search term "Physical Activity Measurement."

CONCLUSIONS

Physical activity is a lifestyle factor that is a key focus in chronic disease-related research, prevention, and interventions. Healthy People 2010 set goals of decreasing the prevalence of preventable diseases by encouraging healthier lifestyle patterns. Shifts toward more sedentary lifestyles have resulted in increases in life-limiting disease states, including obesity, diabetes, heart disease, cancer, and osteoporosis. Physical activity measurements have been used widely in research studies but are less commonly used in primary care. Measuring individuals' physical activity levels as part of the health assessment will enhance the provider's ability to engage in health promotion and suggest health protection interventions. The strengths, weaknesses, and potential applications to practice of physical activity measures are summarized in an effort to familiarize nurse practitioners (NPs) with commonly used tools and encourage integration of physical activity assessment into their current practice.

IMPLICATIONS FOR PRACTICE

NPs are in an ideal position to promote health by encouraging appropriate amounts of physical activity. Screening, health promotion, and disease prevention are part of the core competencies of NP practice established by the National Organization of Nurse Practitioner Faculties. Increased knowledge of physical activity measures will enhance the NP's ability to evaluate relevant physical activity research for use in evidence-based practice. Incorporation of simple yet appropriate physical activity measurements into practice will expand the NP's ability to identify and thus address sedentary lifestyles in their clientele.

Adherence to healthy lifestyle habits in US adults, 1988-2006

BACKGROUND

Lifestyle choices are associated with cardiovascular disease and mortality. The purpose of this study was to compare adherence to healthy lifestyle habits in adults between 1988 and 2006.

METHODS

Analysis of adherence to 5 healthy lifestyle trends (>or=5 fruits and vegetables/day, regular exercise >12 times/month, maintaining healthy weight [body mass index 18.5-29.9 kg/m(2)], moderate alcohol consumption [up to 1 drink/day for women, 2/day for men] and not smoking) in the National Health and Nutrition Examination Survey 1988-1994 were compared with results from the National Health and Nutrition Examination Survey 2001-2006 among adults aged 40-74 years.

RESULTS

Over the last 18 years, the percent of adults aged 40-74 years with a body mass index >or=30 kg/m(2) has increased from 28% to 36% (P <.05); physical activity 12 times a month or more has decreased from 53% to 43% (P <.05); smoking rates have not changed (26.9% to 26.1%); eating 5 or more fruits and vegetables a day has decreased from 42% to 26% (P <.05), and moderate alcohol use has increased from 40% to 51% (P <.05). Adherence to all 5 healthy habits has gone from 15% to 8% (P <.05). Although adherence to a healthy lifestyle was lower among minorities, adherence decreased more among non-Hispanic Whites over the period. Individuals with a history of hypertension/diabetes/cardiovascular disease were no more likely to be adherent to a healthy lifestyle than people without these conditions.

CONCLUSIONS

Generally, adherence to a healthy lifestyle pattern has decreased during the last 18 years, with decreases documented in 3 of 5 healthy lifestyle habits. These findings have broad implications for the future risk of cardiovascular disease in adults.

The freshman weight gain phenomenon revisited

Earlier studies associated the first year of college with a dramatic increase in body weight, termed the "freshman 15". However, recent studies showed that weight gain might be smaller. The purpose of this review was to evaluate the extent of observed weight/body composition changes, including factors associated with them, among students entering university. Searches were conducted for studies examining weight/body composition changes during freshman semesters. Most studies were not comprehensive in assessing numerous potential causative factors for weight gain. Methods for assessing diet, physical activity, and behavioral factors varied among studies. Weight changes were often not quantified by measures of body composition (lean/fat) to ascertain that changes were limited just to gains in fat mass. Overall, weight changes ranged from 0.7-3.1 kg, but among individuals who gained weight, the range was narrower, 3.1-3.4 kg. There may be specific groups of students with a greater predisposition for weight gain and future research should focus on identifying those groups.

Objectively assessed physical activity and aerobic fitness in a population-based sample of Norwegian 9- and 15-year-olds

The present study described current physical activity, determined compliance with physical activity guidelines and assessed aerobic fitness in a nationally representative sample of 9- and 15-year-olds in Norway. In 2005-2006, 2299 children and adolescents were randomly recruited. The participation rate was 89% and 74% among the 9- and 15-year-olds, respectively. Physical activity was assessed objectively by accelerometry, and aerobic fitness was measured directly as peak oxygen uptake during a cycle ergometry test. Boys were more physically active than girls, and 9-year-olds were substantially more active than 15-year-olds. Physical activity was higher during weekdays than weekends, and 9-year-olds were most active during spring. While four out of five children met current physical activity guidelines, only half of the adolescents did. The mean (SD) values for peak VO2 were: 9-year-old boys, 48.2 (7.1) mL/min/kg; 9-year-old girls, 42.9 (6.7) mL/min/kg; and 15-year-old girls 41.1 (6.0) mL/min/kg and 15-year-old boys 51.9 (8.0) mL/min/kg. Because of the high participation rate, this study provides a good description of the physical activity and aerobic fitness in the young population. Finally, girls and adolescents seem appropriate targets when promoting physical activity in order to increase the proportion meeting the recommendations.

Relation of school environment and policy to adolescent physical activity

BACKGROUND

Physical activity (PA) declines as children and adolescents age. The purpose of this study was to examine how specific school factors relate to youth PA, TV viewing, and body mass index (BMI).

METHODS

A sample of 12- to 18-year-old adolescents in 3 cities (N = 165, 53% females, mean age 14.6 +/- 1.7 years, 44% nonwhite) completed surveys assessing days of physical education (PE) class per week, school equipment accessibility, after-school supervised PA, and after-school field access. Regression analyses were conducted to examine relationships between these school factors and PA at school facilities open to the public (never active vs active), overall PA level (days per week physically active for 60 minutes), BMI z score, and TV watching (hours per week).

RESULTS

Adjusting for demographics, days of PE per week and access to school fields after school were correlated with overall PA (beta= 0.286, p = .002, semipartial correlation .236 and beta= 0.801, p = .016, semipartial correlation .186, respectively). The association between after-school field access and overall PA was mediated by use of publicly accessible school facilities for PA. After-school supervised PA and school PA equipment were not associated with overall PA. In adjusted regression analyses including all school factors, days of PE remained correlated to overall PA independent of other school factors (beta= 0.264, p = .007, semipartial correlation = .136). There were no associations between school factors and BMI or TV watching.

CONCLUSIONS

Based on these study findings, PE is a promising intervention to address improving overall adolescent PA within the school setting.

Disagreement in physical activity assessed by accelerometer and self-report in subgroups of age, gender, education and weight status

BACKGROUND

The purpose of this study is to compare self-reported time (by questionnaire) and objectively measured time (by accelerometer) spent on physical activity at moderate (MPA) and vigorous intensity (VPA) in subgroups of age, gender, education and weight status.

METHODS

In total, 236 adolescents (aged 12-18) and 301 adults (aged 22-40), completed the questionnaire and wore an accelerometer for two weeks.

RESULTS

Adolescents reported exceptionally more time spent on MPA (mean difference 596 +/- 704 min/wk) and VPA (mean difference 178 +/- 315 min/wk) than was assessed objectively by the accelerometer. Based on the questionnaire, high educated adolescents spent more time on MPA (205 min/wk, p = 0.002) and VPA (120 min/wk, p = 0.01) than low educated adolescents, but according to the accelerometer they spent less time on MPA (149 min/wk, p = 0.001) and VPA (47 min/wk, p = 0.001). Among adults there was moderate agreement between self-reported time and objectively measured time spent on MPA, but in general the reported time spent on MPA (mean difference 107 +/- 334 min/wk) and VPA (mean difference 169 +/- 250 min/wk) exceeded the time measured with the accelerometer. Overweight adults reported significantly more VPA (57 min/wk, p = 0.04) than normal weight adults, but this was not confirmed by the accelerometer data.

CONCLUSION

We observed large differences in time spent on MPA and VPA measured by questionnaire and accelerometer in adolescents but reasonably good agreement in adults. Differences between methods varied by gender, education and weight status. This finding raises serious questions about the use of questionnaires to quantify MPA and VPA in adolescents. There is a clear need in advanced valid assessments of PA in adolescents.

TRIAL NUMBER

ISRCTN93896459.

Increasing physical activity in postpartum multiethnic women in Hawaii: results from a pilot study

BACKGROUND

Mothers of an infant are much less likely to exercise regularly compared to other women. This study tested the efficacy of a brief tailored intervention to increase physical activity (PA) in women 3-12 months after childbirth. The study used a pretest-posttest design. Sedentary women (n = 20) were recruited from a parenting organization. Half the participants were ethnic minorities, mean age was 33 +/- 3.8, infants' mean age was 6.9 +/- 2.4 months, 50% were primiparas, and mean body mass index was 23.6 +/- 4.2.

METHODS

The two-month intervention included telephone counseling, pedometers, referral to community PA resources, social support, email advice on PA/pedometer goals, and newsletters.The primary outcome of the study was minutes per week of moderate and vigorous leisure-time physical activity measured by the Godin physical activity instrument.

RESULTS

All women (100%) returned for post-test measures; thus, paired t-tests were used for pre-post increase in minutes of moderate and vigorous leisure-time physical activity and comparisons of moderate and vigorous leisure-time physical activity increases among ethnic groups. At baseline participants' reported a mean of 3 +/- 13.4 minutes per week moderate and vigorous leisure-time physical activity. At post-test this significantly increased to 85.5 +/- 76.4 minutes per week of moderate and vigorous leisure-time physical activity (p < .001, Cohen's d = 2.2; effect size r = 0.7). There were no differences in pre to post increases in minutes of moderate and vigorous leisure-time physical activity among races.

CONCLUSION

A telephone/email intervention tailored to meet the needs of postpartum women was effective in increasing physical activity levels. However, randomized trials comparing tailored telephone and email interventions to standard care and including long-term follow-up to determine maintenance of physical activity are warranted.

Stability of physical activity across the lifespan

Physical activity is associated with various health-relevant psychosocial and physiological processes, but activity stability across extended time periods is inadequately understood. This lifespan longitudinal cohort study examined activity levels of 723 males and 554 females. Associations across time were computed and structural equation modeling compared a one factor model and a simplex model. Results showed activity levels are somewhat stable from childhood through middle and late adulthood. Further, a simplex model provided a better fit than a one factor model. Successful models and interventions to improve health will likely require a more nuanced, pattern-sensitive understanding of physical activity across time.

Optimising lifestyle interventions: identification of health behaviour patterns by cluster analysis in a German 50+ survey

BACKGROUND

Many prevention and intervention measures are still targeting isolated behaviours such as tobacco use or physical inactivity. Cluster analysis enables the aggregation of single health behaviours in order to identify distinctive behaviour patterns. The purpose of this study was to group a sample of the over-50 population into clusters that exhibit specific health behaviour patterns regarding regular tobacco use, excessive alcohol consumption, unhealthy diet and physical inactivity.

METHODS

From the total population of the federal state of Baden-Wuerttemberg, Germany, 982 men and 1020 women aged 50-70 were randomly selected. Subjects were asked by trained interviewers in computer-assisted telephone interviews (CATI) about health behaviour and sociodemographic characteristics. Cluster analysis was conducted to identify distinct health behaviour patterns. Multinomial logistic regression was used to characterize clusters by specific social attributes.

RESULTS

Five homogeneous health behaviour clusters were identified: 'No Risk Behaviours' (25.3%), 'Physically Inactives' (21.1%), 'Fruit and Vegetable Avoiders' (18.2%), 'Smokers with Risk Behaviours' (12.7%) and 'Drinkers with Risk Behaviours' (22.7%). Whereas the first cluster is the ideal in terms of risk and prevention, the latter two groups include regular users of tobacco and excessive consumers of alcohol, who also engage in other risk behaviours like inactivity and maintaining an unhealthy diet. These two risk groups also exhibit specific sociodemographic attributes (male, living alone, social class affiliation).

CONCLUSION

Unhealthy behaviours evidently occur in typical combinations. An awareness of this clustering enables prevention and intervention measures to be planned so that multiple behaviours can be modified simultaneously.