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

Associations of psychosocial factors with health outcomes among youth with cystic fibrosis

PURPOSE

The purpose of this study was to examine the relationship of strains, resources, feelings, and behaviors about treatment adherence reported by youth with cystic fibrosis (CF) with repeated clinic measures of their pulmonary function and nutritional status.

METHODS

Linear mixed models, stratified by gender, adjusting for age, were used to examine the effects of strains, resources, and adherence behaviors on repeated pulmonary function and nutritional status measures. All 10-21 years old with CF at the Minnesota Cystic Fibrosis Center were invited by mail to participate. Of these 177 youth, 51% (43 boys, 47 girls) returned surveys. Forced expiratory volume in 1 sec and predicted weight-for-height were extracted from participants' clinic records for the 18 months following receipt of the survey.

RESULTS

Females showed significantly greater variability in repeated measures of pulmonary function and nutritional status compared to males. Parent-youth strains, physical strains, activity limitations, and cough suppression had significant effects on the 18-month mean of pulmonary function measures for females, but only physical strains had a significant effect for males.

CONCLUSION

Compared to males, females experienced more strains and poorer treatment adherence, which may be factors associated with declines in pulmonary function observed among females with CF during the adolescent years.

Change in physical education motivation and physical activity behavior during middle school

PURPOSE

To test a mediational model of the relationships among motivation-related variables in middle-school physical education and leisure-time physical activity behavior.

METHODS

Sixth- and seventh-grade physical education students from five middle schools in the midwest United States completed a survey containing measures of study variables on two occasions, 1 year apart.

RESULTS

Motivation-related constructs positively predicted leisure-time physical activity behavior. Enjoyment of activities in physical education and physical activity during class mediated the relationship between self-determined motivation in physical education and leisure-time physical activity. Perceived competence, autonomy, and relatedness were important antecedent variables in the model, with autonomy and relatedness showing less stability over time and positively predicting self-determined motivation.

CONCLUSIONS

Students' leisure-time physical activity is linked to motivation-related experiences in physical education. Perceptions of competence, autonomy, and relatedness, self-determined motivation, enjoyment, and physical activity in the physical education setting directly or indirectly predict leisure-time physical activity. The associations suggest that more adaptive motivation corresponds to transfer of behavior across contexts. Also, the findings suggest that the efficacy of school-based physical activity interventions, within and outside of school, is linked to the degree of support for students' self-determined motivation.

Lifestyle physical activity of older rural women

The purpose of this study was to describe and examine the lifestyle physical activity behaviors (household, leisure, occupational) of older rural women. Background characteristics included demographics, environment, social support, and health. Intrapersonal characteristics included motivation and self-efficacy. The majority of the women's energy expenditure was in the household dimension. Social support was positively associated with household activities. A higher level of leisure physical activity was associated with living within the two small cities and reporting lower levels of health and lower motivation. This research highlights the importance of household physical activity and the contribution of social support for household physical activity, both of which may be important in developing interventions to promote physical activity in older rural women.

Self-efficacy moderates the relation between declines in physical activity and perceived social support in high school girls

OBJECTIVE

To test whether self-efficacy for overcoming barriers to physical activity has direct, indirect (i.e., mediated), or moderating relations with naturally occurring change in perceived social support and declines in physical activity during high school.

METHODS

Latent growth modeling was used with measures completed in the 8th, 9th, and 12th grades by a cohort of 195 Black and White girls.

RESULTS

Self-efficacy was stable and moderated the relation between changes in physical activity and perceived social support. Girls who maintained a perception of strong social support had less of a decline in physical activity if they also had high self-efficacy. However, girls having high self-efficacy had a greater decline in physical activity if they perceived declines in social support.

CONCLUSIONS

Randomized controlled trials of physical activity interventions based on social cognitive theory should consider that the influence of girls' perceptions of social support on their physical activity may differ according to their efficacy beliefs about barriers to physical activity.

Increasing walking in college students using a pedometer intervention: differences according to body mass index

OBJECTIVE

The researchers assessed the effectiveness of a pedometer intervention and differences in walking behaviors according to body mass index (BMI).

PARTICIPANTS

Two hundred ninety college students completed the intervention from January to February 2005.

METHODS

Participants wore pedometers 5 days per week for 12 weeks and completed questionnaires assessing demographic information. The authors calculated daily step averages for weeks 1, 6, and 12. They then classified students as underweight (UW), normal weight (NW), or overweight/obese, by BMI. The authors analyzed data using repeated-measures analysis of variance.

RESULTS

The average number of daily steps increased from week 1 to week 6 (p < .001) and week 12 (p = .002). UW participants reported the fewest steps at each time point, but the difference was significant only when compared with NW participants (p = .03).

CONCLUSIONS

These results support the effectiveness of a pedometer intervention to increase walking in college students. Health benefits other than weight management should be emphasized to maximize the effects for all students.

Tracking of pedometer-determined physical activity in adults who relocate: results from RESIDE

Background

This secondary analysis investigated the extent and pattern of one-year tracking of pedometer-determined physical activity in people who relocated within the same metropolitan area (T1: baseline and T2: post-relocation). Specifically, data were derived from the RESIDential Environment Project (RESIDE), a natural experiment of people moving into new housing developments.

Methods

1,175 participants (491 males, age = 42.6 ± 12.7 years, BMI = 27.2 ± 9.9 kg/m²; 684 females, age = 41.2 ± 11.3 years, BMI = 25.4 ± 5.2 kg/m²) wore a Yamax pedometer (SW-200-024) for seven days during the same season at both time points. Pearson's product-moment and Spearman's rank order correlations were used to evaluate the extent of tracking of mean steps/day. Age categories were set as youngest-29.9 (19 was the youngest in males, 20 in females), 30–39.9, 40–49.9, 50–59.9, and 60-oldest (78 was the oldest in males, 71 in females). Change in steps/day was also described categorically as: 1) stably inactive < 7,500 steps/day; 2) decreased activity (moved from ≥ 7,500 to < 7,500 steps/day between T1 and T2); 3) increased activity (moved from < 7,500 to ≥ 7,500 steps/day between T1 and T2); and, 4) stably active ≥ 7,500 steps/day at both time points. Stratified analyses were used to illuminate patterns by sex, age, and BMI-defined weight categories.

Results

Overall, there was a small (non-significant) decrease in steps/day between T1 and T2 (mean ± SD is -81 ± 3,090 with 95%CI -259 to 97). With few exceptions (i.e., older women), both Pearson's and Spearman's correlations were moderate (r = 0.30–0.59) to moderately high (r = 0.60–0.70). The relative change/stability in steps/day (cut at 7,500 steps/day) was not significant across age groups in males (χ² = 17.35, p = .137) but was in females (χ² = 50.00, p < .0001). In both males and females the differences across BMI categories was significant (χ² = 22.28, p = .001 and χ² = 15.70, p = .015, respectively). For both sexes, those in the obese category were more stably inactive (and less stably active) between assessment points compared with those who were categorized as normal weight.

Conclusion

Despite relocation, Western Australian adults held their rank position to a moderate to moderately high extent over one year. Categorized and expressed as relative stability/change over time, sex, age, and BMI patterns were evident.

Content specificity of expectancy beliefs and task values in elementary physical education

The curriculum may superimpose a content-specific context that mediates motivation (Bong, 2001). This study examined content specificity of the expectancy-value motivation in elementary school physical education. Students' expectancy beliefs and perceived task values from a cardiorespiratory fitness unit, a muscular fitness unit, and a traditional skill/game unit were analyzed using constant comparison coding procedures, multivariate analysis of variance, X2, and correlation analyses. There was no difference in the intrinsic interest value among the three content conditions. Expectancy belief attainment, and utility values were significantly higher for the cardiorespiratory fitness curriculum. Correlations differentiated among the expectancy-value components of the content conditions, providing further evidence of content specificity in the expectancy-value motivation process. The findings suggest that expectancy beliefs and task values should be incorporated in the theoretical platform for curriculum development based on the learning outcomes that can be specified with enhanced motivation effect.

Black, Hispanic, and white girls' perceptions of environmental and social support and enjoyment of physical activity

BACKGROUND

This study examines the differences among black, Hispanic, and white adolescent girls in their perceptions surrounding physical activity (PA), including support within the school climate, friend and family social support, and personal enjoyment.

METHODS

Participants included 1466 sixth-grade girls from 36 middle schools across the United States. Participants were 20% black, 21% Hispanic, 47% white, and 12% of other or mixed races. Multivariate analyses were performed on each scale, adjusting for body mass index and free and reduced-price lunch status.

RESULTS

Results showed racial differences on several variables. Black girls, compared with white girls, perceived significantly lower PA enjoyment (p<.001) and teacher support for PA (p=.004). Hispanic girls experienced less PA enjoyment (p=.003) and perceived less support for PA from boys (p=.001) and their families (p=.008) than white girls. Black girls reported significantly higher levels of physical education (PE) enjoyment than did white girls (p=.003).

CONCLUSIONS

Differences in perceived PA support and enjoyment across race raise questions about why these differences exist and how best to address disparities within interventions.

Patterns and determinants of physical activity in U.S. adolescents

PURPOSE

The objectives of this study were to describe longitudinal trends in adolescent physical activity in a sample of U.S. adolescents and to assess the effect of multiple individual, parental, and environmental factors on initial level and rates of change in adolescent physical activity.

METHODS

Study subjects were 12,812 boys and girls 10 to 18 years of age who were participating in the Growing Up Today Study and their mothers. We used accelerated longitudinal analysis to describe trajectories of physical activity from 1997-1999, and random effects linear mixed models to determine which factors were independently associated with baseline physical activity and changes in physical activity over time.

RESULTS

Mean hours of physical activity ranged from 7.3-11.6 hours per week in boys and from 8.0-11.2 hours per week in girls. Physical activity was best modeled as a quadratic function of age, increasing until early adolescence and declining after age 13 in boys and girls. Multivariable modeling demonstrated that variables associated with physical activity level at baseline in boys and girls were age, body mass index, psychosocial variables, personal attitudes about body shape, perceived peer attitudes about body shape/fitness, parental attitudes about physical activity, parental physical activity, and environmental barriers to physical activity. Age was the only factor that predicted change in physical activity over time.

CONCLUSIONS

Interventions to increase physical activity in adolescents should begin before adolescence. Interventions may be more effective if they are multimodal and focus on modifiable individual, parental, and environmental factors.

Amount of time spent in sedentary behaviors in the United States, 2003-2004

Sedentary behaviors are linked to adverse health outcomes, but the total amount of time spent in these behaviors in the United States has not been objectively quantified. The authors evaluated participants from the 2003-2004 National Health and Nutrition Examination Survey aged >/=6 years who wore an activity monitor for up to 7 days. Among 6,329 participants with at least one 10-hour day of monitor wear, the average monitor-wearing time was 13.9 hours/day (standard deviation, 1.9). Overall, participants spent 54.9% of their monitored time, or 7.7 hours/day, in sedentary behaviors. The most sedentary groups in the United States were older adolescents and adults aged >/=60 years, and they spent about 60% of their waking time in sedentary pursuits. Females were more sedentary than males before age 30 years, but this pattern was reversed after age 60 years. Mexican-American adults were significantly less sedentary than other US adults, and White and Black females were similarly sedentary after age 12 years. These data provide the first objective measure of the amount of time spent in sedentary behavior in the US population and indicate that Americans spend the majority of their time in behaviors that expend very little energy.

A Review of TV Viewing and Its Association With Health Outcomes in Adults

Observational studies of the relationship between TV viewing and health outcomes (overweight/obesity, cholesterol/lipids, blood pressure/hypertension, type 2 diabetes, and metabolic syndrome) in adults are reviewed. Studies indicate that in adults, greater amounts of TV viewing are consistently associated with increased overweight risk, both cross-sectionally and longitudinally, but that results are mixed regarding the relationship between adult TV viewing and other health outcomes. It is theorized that greater TV viewing is related to increased weight status and poorer health outcomes by reducing energy expenditure, predominantly through reducing time spent in physical activity, and increasing energy intake. No randomized trials that manipulated TV viewing time measured the effects of this manipulation on diet and physical activity and then measured future health outcomes in adults. However, experimental studies, predominantly conducted in children, show relationships between TV viewing, energy intake, physical activity, and weight status, which follow the hypothesized mechanisms. Interventions targeting TV viewing in adults appear to be justified, and proposed methods for conducting these interventions, as well as potential barriers to implementing these interventions, are discussed.

[Instrument for the assessment of middle-aged and older adults' physical activity: design, eliability and application of the German-PAQ-50+]

Existing physical activity questionnaires have focused either on young and middle-aged adults or on the elderly. They have mainly assessed only a portion of possible physical activities or contained nation-specific sports. As there is no gold standard for a questionnaire-based assessment of physical activity in the over-50 population, recommendations for such a questionnaire relating to German-speaking countries were developed. This work included a systematic literature research, a survey of experts, and the design of a questionnaire based on validated measuring instruments. Finally, to test its reliability and application in the field, the complete questionnaire, including a retest, was applied by telephone interview (n = 57). The test-retest-correlation was r = 0.60 for the total time of physical activity and r = 0.52 for total energy expenditure. The researchers determined that the instrument is comprehensive in its coverage of all relevant domains of physical activity for the over-50 population; it is economically feasible and showed good acceptance.

Promoting physical activity in middle school girls: Trial of Activity for Adolescent Girls

BACKGROUND

Physical activity is important for weight control and good health; however, activity levels decline in the adolescent years, particularly in girls.

DESIGN

Group randomized controlled trial.

SETTING/PARTICIPANTS

Middle school girls with English-speaking skills and no conditions to prevent participation in physical activity in 36 schools in six geographically diverse areas of the United States. Random, cross-sectional samples were drawn within schools: 6th graders in 2003 (n=1721) and 8th graders in 2005 (n=3504) and 2006 (n=3502).

INTERVENTION

A 2-year study-directed intervention (fall 2003 to spring 2005) targeted schools, community agencies, and girls to increase opportunities, support, and incentives for increased physical activity. Components included programs linking schools and community agencies, physical education, health education, and social marketing. A third-year intervention used school and community personnel to direct intervention activities.

MAIN OUTCOME MEASURES

The primary outcome, daily MET-weighted minutes of moderate-to-vigorous physical activity (MET-weighted MVPA), was assessed using accelerometry. Percent body fat was assessed using anthropometry.

RESULTS

After the staff-directed intervention (pre-stated primary outcome), there were no differences (mean= -0.4, 95% CI= -8.2 to 7.4) in adjusted MET-weighted MVPA between 8th-grade girls in schools assigned to intervention or control. Following the Program Champion-directed intervention, girls in intervention schools were more physically active than girls in control schools (mean difference 10.9 MET-weighted minutes of MVPA, 95% CI=0.52-21.2). This difference is about 1.6 minutes of daily MVPA or 80 kcal per week. There were no differences in fitness or percent body fat at either 8th-grade timepoint.

CONCLUSION

A school-based, community-linked intervention modestly improved physical activity in girls.

Gender differences in treatment adherence among youth with cystic fibrosis: Development of a new questionnaire

BACKGROUND

Some prior studies have reported that girls with cystic fibrosis (CF) experience higher morbidity and mortality compared to boys. In this study, the authors compared boys' and girls' perceptions of disease-related strains and resources associated with living with CF, and the relationship of these factors to CF treatment feelings and behaviors.

METHODS

All 10-21 year olds with CF at the Minnesota Cystic Fibrosis Center were invited by mail to complete a new self-report survey (Living with CF Questionnaire--LCFQ). Of these 177 youth, 58% (49 boys and 54 girls) returned surveys.

RESULTS

Exploratory and confirmatory factor analyses revealed nine factors in the LCFQ. Partial support was found for hypothesized gender differences in these factors. Compared to boys, girls reported significantly more illness-related strains and worries, including emotional strains, greater treatment discouragement, lower self-esteem, and lower adherence to some aspects of the CF treatment regimen (coughing, eating high-fat foods, taking meds/pills).

CONCLUSIONS

Living with CF appears to have a greater emotional impact on adolescent girls compared to boys. These gender differences may contribute to the poorer pulmonary function observed among girls with cystic fibrosis during the adolescent years.

Campus walkability, pedometer-determined steps, and moderate-to-vigorous physical activity: a comparison of 2 university campuses

OBJECTIVE AND PARTICIPANTS

At 2 Arizona State University (ASU) campuses, the authors measured student activity and distance walked on campus, as well as student-reported walkability around the student union.

METHODS

Students from ASU-Polytechnic (n = 20, 33% male) and ASU-Tempe (n = 20, 60% male) recorded distance walked on campus and wore physical activity monitors for 5 days.

RESULTS

Polytechnic students spent an average of 36.9 minutes in moderate-to-vigorous physical activity each week; Tempe students spent 69.5 minutes (p < .001). At Polytechnic, students walked an average of 7,674 steps per weekday; at Tempe, 11,294 steps (p = .003). Female students at Polytechnic walked an average of 1.3 km/d; at Tempe, 4.3 km/d (p < .001). At Polytechnic, men walked an average of 1.4 km/d; at Tempe, 3.1 km/d (p = .03). Tempe students rated campus walk-ability as very good, whereas Polytechnic students rated it fair (p < .001).

CONCLUSIONS

Students at both campuses met activity recommendations; noted differences may be attributed to the built environment's contribution to walkability.

Age and sex differences in physical activity of Portuguese adolescents

PURPOSE

This study sought to examine sex- and age-associated variations in physical activity (PA) among Portuguese adolescents aged 10-18 yr.

METHODS

A total of 12,577 males and females at the primary or secondary education level were sampled across four regions of Portugal. PA was assessed by a questionnaire, producing four different indexes: work/school (WSI), sport (SI), leisure time (LI), and total physical activity index (PAI). We examined sex and age differences by using two-way analysis of variance.

RESULTS

Males had higher mean values of PA than did females. In both sexes, mean values for all four PA indexes increased from ages 10 to 16 yr. After age 16, females decreased their mean values, whereas males continued to increase their values (except for LI). In both sexes, the average annual rate of change for the mean values of all four PA indexes correspond to three sensitive age periods (10-13, 13-16, and 16-18 yr). Until age 16, average mean changes for females ranged from +0.7 to +1.6% per year, except for SI in the youngest group (a modest decrease). For males under 16 yr, the pattern was similar, with increases ranging from 0.4 to 1.9% per year. After age 16, females experienced decreases of 1-2.1% per year for the four PA indexes, whereas males showed an increase for three indexes and an average decrease of 1.3% per year for LI.

CONCLUSIONS

These results suggest that it is important to consider sex differences in PA levels among Portuguese adolescents. Unlike their male counterparts, Portuguese females may reduce much of their PA during late adolescence.

Development and evaluation of the physical activity questionnaire for elderly Japanese: the Nakanojo study

The Physical Activity Questionnaire for Elderly Japanese (PAQ-EJ) is a self-administered physical activity questionnaire for elderly Japanese; the authors report here on its repeatability and direct and indirect validity. Reliability was assessed by repeat administration after 1 month. Direct validation was based on accelerometer data collected every 4 s for 1 month in 147 individuals age 65-85 years. Indirect validation against a 10-item Barthel index (activities of daily living [ADL]) was completed in 3,084 individuals age 65-99 years. The test-retest coefficient was high (r = .64-.71). Total and subtotal scores for lower (transportation, housework, and labor) and higher intensity activities (exercise/sports) were significantly correlated with step counts and durations of physical activity <3 and >or=3 METs (r = .41, .28, .53), respectively. Controlling for age and ADL, scores for transportation, exercise/sports, and labor were greater in men, but women performed more housework. Sex- and ADL- or age-adjusted PAQ-EJ scores were significantly lower in older and dependent people. PAQ-EJ repeatability and validity seem comparable to those of instruments used in Western epidemiological studies.

Social inequalities in changes in health-related behaviour among Slovak adolescents aged between 15 and 19: a longitudinal study

Background

Lower socioeconomic position is generally associated with higher rates of smoking and alcohol consumption and lower levels of physical activity. Health-related behaviour is usually established during late childhood and adolescence. The aim of this study is to explore changes in health-related behaviour in a cohort of adolescents aged between 15 and 19, overall and by socioeconomic position.

Methods

The sample consisted of 844 first-year students (42.8% males, baseline in 1998 – mean age 14.9, follow-up in 2002 – mean age 18.8) from 31 secondary schools located in Kosice, Slovakia. This study focuses on changes in adolescents' smoking, alcohol use, experience with marijuana and lack of physical exercise with regard to their socioeconomic position. Four indicators of socioeconomic position were used – adolescents' current education level and employment status, and the highest education level and highest occupational status of their parents. We first made cross tabulations of HRB with these four indicators, using McNemar's test to assess differences. Next, we used logistic regression to assess adjusted associations, using likelihood ratio tests to assess statistical significance.

Results

Statistically significant increases were found in all health-related behaviours. Among males, the most obvious socioeconomic gradient was found in smoking, both at age 15 and at 19. Variations in socioeconomic differences in health-related behaviour were more apparent among females. Although at age 15, almost no socioeconomic differences in health-related behaviour were found, at age 19 differences were found for almost all socioeconomic indicators. Among males, only traditional socioeconomic gradients were found (the lower the socioeconomic position, the higher the prevalence of potentially harmful health-related behaviour), while among females reverse socioeconomic gradients were also found.

Conclusion

We confirmed an increase in unhealthy health-related behaviour during adolescence. This increase was related to socioeconomic position, and was more apparent in females.

Advanced pubertal status at age 11 and lower physical activity in adolescent girls

OBJECTIVE

To examine the relationship between pubertal timing and physical activity.

STUDY DESIGN

A longitudinal sample of 143 adolescent girls was assessed at ages 11 and 13 years. Girls' pubertal development was assessed at age 11 with blood estradiol levels, Tanner breast staging criteria, and parental report of pubertal development. Girls were classified as early maturers (n = 41) or later maturers (n = 102) on the basis of their scores on the 3 pubertal development measures. Dependent variables measured at age 13 were average minutes/day of moderate to vigorous and vigorous physical activity as measured by the ActiGraph accelerometer.

RESULTS

Early-maturing girls had significantly lower self-reported physical activity and accumulated fewer minutes of moderate to vigorous and vigorous physical activity and accelerometer counts per day at age 13 than later maturing girls. These effects were independent of differences in percentage body fat and self-reported physical activity at age 11.

CONCLUSION

Girls experiencing early pubertal maturation at age 11 reported lower subsequent physical activity at age 13 than their later maturing peers. Pubertal maturation, in particular early maturation relative to peers, may lead to declines in physical activity among adolescent girls.

Sports participation and physical education in American secondary schools: current levels and racial/ethnic and socioeconomic disparities

BACKGROUND

The purpose of this study was to determine the current levels of physical education (PE) and sports participation among American secondary school students, and to establish the extent to which they vary by grade level, racial/ethnic background, and socioeconomic status (SES) of the students.

METHODS

Nationally representative data were used from over 500 schools and 54,000 students surveyed in 2003, 2004, and 2005 as part of the Youth, Education, and Society (YES) study and the Monitoring the Future (MTF) study. As part of YES, school administrators completed questionnaires on physical activity (including rates of sports and PE participation) of students in their schools. Students in the same schools completed self-administered questionnaires in the same year as part of MTF, providing individual background data, including their gender, racial/ethnic identification, and parents' education level. Data were analyzed in 2006.

RESULTS

Physical education requirements, and actual student participation rates, decline substantially between 8th and 12th grades. About 87% of 8th graders were in schools that required them to take PE, compared to only 20% of 12th graders. Principals estimate that over 90% of 8th graders actually take PE, compared to 34% of 12th graders. Subgroup differences in PE participation rates were small. Only a fraction of all students participate in varsity sports during the school year, with girls participating only slightly less than boys (33% vs 37%). Participation correlates negatively with SES and was lower among black and Hispanic students than white students, even after controlling for other variables. Participation rates in intramural sports were even lower, declined in higher grades, and were lower among low-SES and Hispanic students (after controlling for other variables).

CONCLUSIONS

Physical education is noticeably lacking in American high schools for all groups. Racial/ethnic minorities and low-SES youth, who are at higher than average risk of being overweight in adolescence, are getting less exercise due to their lower participation in school sports. Disparities in resources available to minorities and lower-SES youth may help explain the differences in participation rates.

Physical education and physical activity: results from the School Health Policies and Programs Study 2006

BACKGROUND

Comprehensive school-based physical activity programs consist of physical education and other physical activity opportunities including recess and other physical activity breaks, intramurals, interscholastic sports, and walk and bike to school initiatives. This article describes the characteristics of school physical education and physical activity policies and programs in the United States at the state, district, school, and classroom levels.

METHODS

The Centers for Disease Control and Prevention conducts the School Health Policies and Programs Study every 6 years. In 2006, computer-assisted telephone interviews or self-administered mail questionnaires were completed by state education agency personnel in all 50 states plus the District of Columbia and among a nationally representative sample of districts (n=453). Computer-assisted personal interviews were conducted with personnel in a nationally representative sample of elementary, middle, and high schools (n=988) and with a nationally representative sample of teachers of required physical education classes and courses (n=1194).

RESULTS

Most states and districts had adopted a policy stating that schools will teach physical education; however, few schools provided daily physical education. Additionally, many states, districts, and schools allowed students to be exempt from participating in physical education. Most schools provided some opportunities for students to be physically active outside physical education. Staff development for physical education was offered by states and districts, but physical education teachers generally did not receive staff development on a variety of important topics.

CONCLUSIONS

To enhance physical education and physical activity in schools, a comprehensive approach at the state, district, school, and classroom levels is necessary. Policies, practices, and comprehensive staff development at the state and district levels might enable schools to improve opportunities for students to become physically active adults.

Do children take the same number of steps every day?

The purpose of this study was to examine the day-to-day variability in pedometer-assessed physical activity (steps/day). A total of 1,443 children aged 6-12 years from the United States (195 boys, 254 girls), Sweden (257 boys, 252 girls), and Australia (229 boys, 256 girls) wore a pedometer for 4 consecutive weekdays. Repeated measures analysis of variance was used to examine daily differences in steps/day and the coefficient of variation (CV) was calculated for each individual to describe the day-to-day variability. Overall, mean steps/day were higher among boys (14,698 +/- 3,373 steps/day) than girls (12,086 +/- 2,929 steps/day). Significant differences were found between the 4 monitoring days for the entire sample; however, the absolute mean differences were small (55-958 steps) with an overall effect size of 0.01. This trend was apparent regardless of age, gender, and country. Individual CVs ranged from approximately 2 to 88% and the overall mean CV approximated 22%. An age-related increase in the mean CV was observed between 6- and 12-year-old children. The age x gender x country interaction was not significant (P > 0.05). These findings have implications toward the proper design, analysis, and interpretation of studies regarding physical activity among children. Beyond this aspect, our results lend insight into potential age-related biological mechanisms that may also influence daily levels and patterns of physical activity.

Genome-wide linkage scan for exercise participation in Dutch sibling pairs

This study was aimed at identifying the genomic loci linked to exercise participation in males and females. Cross-sectional exercise data of twins and siblings (18-50 years) were used from the Netherlands Twin Registry. The sample consisted of 1432 genotyped sibling pairs from 622 families (1120 sibling pairs were genotyped on all chromosomes). Exercise participation (no/yes, based on a cutoff criterion of four metabolic equivalents and 60 min weekly) was assessed by survey. Genotyping was based on 361 markers and an average marker density of 10.6 cM. Identical by descent status was estimated for a 1 cM grid. A variance components-based sex-limited linkage scan was carried out for exercise participation. The heritability of exercise participation in males was 68.5% and in females 46.3%. The genetic overlap was estimated at 0.32, indicating that partly different genes affect exercise in the two sexes. Suggestive linkage was found in all subjects on chromosome 19p13.3 (LOD=2.18). Although sex differences in linkage effect were not significant, mainly females contributed to the suggestive linkage. The 19p13.3-13.2 region harbors a number of genes related to muscle performance and muscle blood flow, which might affect exercise behavior through exercise ability. Most likely, a large number of genes with each small effects affect exercise participation in males and females. Large collaborative samples are needed to detect these effects.

Physical Activity in Nonoverweight and Overweight Hispanic Children and Adolescents

BACKGROUND

Despite the high prevalence of childhood obesity among U.S. Hispanic children and adolescents, quantitative, objective data on their patterns and levels of physical activity are scarce.

OBJECTIVES

1) To describe qualitatively the types of physical activities in which nonoverweight and overweight Hispanic children and adolescents participate; 2) to use accelerometry to quantitatively describe the duration, intensity, and frequency of physical activity; 3) to examine the influence of age, gender, and BMI status on physical activity levels; and 4) to determine the relationships between physical activity and adiposity, fitness, and risk for the metabolic syndrome.

METHODS

Cross-sectional assessment of physical activity using accelerometers was made for three continuous days in 897 nonoverweight and overweight Hispanic children, ages 4-19 yr. Ancillary measurements included blood pressure, anthropometry, body composition by dual-energy x-ray absorptiometry, fitness by VO2peak test, and metabolic risk factors, using standard clinical and biochemical methods.

RESULTS

Types and levels of physical activity were influenced by age, gender, and body mass index (BMI) status. Total physical activity counts declined markedly with increasing age (P = 0.001) and were consistently higher in boys than in girls (P = 0.001). Total activity counts were lower (P = 0.002) and sedentary activity counts were higher in overweight than in nonoverweight children (P = 0.001). Sleep duration (min.d(-1)) was slightly lower in overweight compared with nonoverweight children, ages 4-8 yr (P = 0.03). Physical activity levels were significantly associated with percent FM, VO2peak, fasting serum insulin, and waist circumference, although the strength of the associations were generally low.

CONCLUSION

Efforts should be made to shift the time in sedentary activity to light activity, and to increase the time spent in moderate to vigorous activity in U.S. Hispanic children and adolescents, with special attention given to the overweight, girls, and adolescents.

Weekend and weekday patterns of physical activity in overweight and normal-weight adolescent girls

OBJECTIVE

To describe the patterns (specifically comparing weekdays and weekends classified by intensities) of physical activity (PA) measured by accelerometry in adolescent girls.

RESEARCH METHODS AND PROCEDURES

Healthy sixth grade girls (n=1603), 11 to 12 years old, were randomly recruited from 36 schools participating in the Trial of Activity in Adolescent Girls. Age, ethnicity, socioeconomic status, weight, and height were taken. PA patterns were measured for 6 days using accelerometry.

RESULTS

Adolescent girls spend most of their time in sedentary (52% to 57% of the day) and light activity (40% to 45% of the day) on weekdays and weekends. In all girls, total PA comprised 44.5% of the day (41.7% light, 2.2% moderate, and 0.7% vigorous) with sedentary activity comprising 55.4%. Moderate-to-vigorous PA (MVPA) was higher (p<0.001) on weekdays than weekends in all girls, but MVPA was lower in at-risk of overweight+overweight girls (p<0.001) on both weekdays and weekends compared with normal-weight girls.

DISCUSSION

Adolescent girls are more active at moderate and vigorous intensities on weekdays than on weekends, and at-risk of overweight and those overweight spend less time engaging in MVPA than normal-weight girls.

The decline in physical activity among adolescent students: a cross-national comparison

BACKGROUND

The decline in physical activity during adolescence is a key public health concern. This comparative study assesses whether the age-related decline in physical activity among high school students occurs similarly in the United States (U.S.) and Ontario, whether the decline in physical activity is steady throughout the age range, or whether any declines are age-specific.

METHODS

Data are based on self-reports of 9th- to 12th-graders derived from the 2001 Youth Risk Behavior Survey (n=13,503) and the 2001 Ontario Student Drug Use Survey (n=1322). Physical activity is measured by the number of days of vigorous physical activity during the past 7 days.

RESULTS

In both samples, there was a dominant and steady decline in physical activity between ages 14 and 18 years. The number of activity days was higher in the U.S. than in Ontario holding constant age and sex. However, a significant sample-by-age interaction showed that the decline in the percentage of U.S. students reporting 3 or more physical activity days was greater than it was in Ontario.

CONCLUSIONS

While the pattern of decline was shown to be similar, the decline was stronger among US adolescents. Future research should examine additional factors influencing the decline in activity and the optimal timing of programs to reduce the decline.

Age and Gender Differences in Youth Physical Activity

PURPOSE

To investigate whether observed gender differences in objectively measured physical activity (PA) in children (8-13 yr) are confounded by physical maturity differences.

METHODS

Four hundred and one children (194 boys and 207 girls) volunteered for this study. An Actigraph accelerometer was used to obtain seven consecutive days of minute-by-minute PA data for each participant. Minutes of moderate to vigorous PA per day (MVPA), continuous minutes of MVPA per day (CMVPA), and minutes of vigorous PA per day (VPA) were derived from the accelerometer data. Age at peak height velocity (APHV), an indicator of somatic maturity, was predicted in all individuals. Gender differences in the PA variables were analyzed using a two-way (gender x age) ANOVA.

RESULTS

Levels of PA decreased with increasing chronological age in both genders (P < 0.05). When aligned on chronological age, boys had a higher MVPA at 10-13 yr, a higher CMVPA at 9-12 yr, and a higher VPA at 9-13 yr (P < 0.05). When aligned on biological age, PA declined with increasing maturity (P < 0.05); however, gender differences between biological age groups disappeared.

CONCLUSION

The observed age-related decline in adolescent boys and girls PA is antithetical to public health goals; as such, it is an important area of research. To fully understand gender disparities in PA, consideration must be given to the confounding effects of physical maturity.

Physical activity and fitness in an international growth standard for preadolescent and adolescent children

Concepts related to energy expenditure, physical activity and physical fitness, and methods of assessment are briefly considered. Variation in energy expenditure, physical activity, and physical fitness associated with age and sex during childhood and adolescence and relationships between physical activity and physical fitness in children and adolescents are reviewed. Implications of undernutrition and obesity for physical activity and physical fitness, and secular changes in physical activity and physical fitness, are briefly highlighted. The review concludes with specific recommendations for and limitations of inclusion of indicators of physical activity and fitness in the construction of an International Growth Standard for Preadolescent and Adolescent Children.

Physical activity-key issues in treatment of childhood obesity

Changes in physical activity with the aim of increasing energy expenditure are usually an important component of childhood obesity treatment. Physical activity also has several other aspects that are positive for the obese child's health, such as improving the metabolic profile and psychological well being. The aim of this paper is to give a short review of what we know about physical activity in paediatric obesity treatment. In addition, practical recommendations will be presented which a health care provider can suggest to obese children and their families with a special focus on daily activity, participation in physical education classes and sports, sedentary behaviours, active commuting to school and how to get family and friends involved in supporting the child.

Health and nutrition education in primary schools in Crete: 10 years' follow-up of serum lipids, physical activity and macronutrient intake

The current study is a 4-year follow-up after the 6-year-long health and nutrition intervention programme applied in the primary schools of Crete. The aim of the current work was to identify whether the benefits obtained in certain health indices at the end of the intervention period were also present 4 years later. From a representative population of 441 pupils (250 from the intervention schools and 191 from the control schools), biochemical, dietary and physical activity data were obtained at baseline, at the end of the intervention period and after intervention (academic years 1992–1993, 1997–1998 and 2001–2002, respectively). The findings of the current study revealed that the favourable changes in serum lipids observed at the end of the intervention period were maintained from baseline to after intervention for total cholesterol (−24·3 (SE 1·65)V. −9·70 (SE 2·03) mg/dl;P=0·001), LDL-cholesterol (−18·6 (SE 1·41)V. −2·49 (SE 1·75) mg/dl;P<0·001), HDL-cholesterol (−8·34 (SE 0·75)V. −9·60 (SE 1·10) mg/dl;P=0·014) and total cholesterol:HDL-cholestrol ratio (0·31 (SE 0·06)V. 0·04 (SE 0·05);P=0·001). Similar favourable changes for the intervention group were observed in leisure-time physical activities (38·3 (SE 11·7)V. −13·2 (SE 10·9) min/week;P=0·038) and BMI (6·05 (SE 0·18)V. 6·67 (SE 0·21) kg/m2;P=0·014), whereas no changes were observed in the fitness and dietary indices examined. The findings of the current study are encouraging, indicating maintenance of the favourable changes observed in serum lipids, BMI and physical activity 4 years after the programme had ended

How active are we? Levels of routine physical activity in children and adults

The accurate measurement of physical activity is fraught with problems in adults, but more especially in children because they have more complex and multi-dimensional activity patterns. In addition, the results of different studies are often difficult to interpret and compare, because of the diversity of methodological approaches, differences in data analysis and reporting, and the adoption of varying definitions of what constitutes an appropriate level of activity. Furthermore, inactivity is seldom quantified directly. Although there exists an extensive literature documenting the health benefits of regular physical activity in adults, activity-health relationships in children are not clear-cut. Current recommendations reinforce the concept of health-related activity, accumulating 30 min moderate-intensity exercise on at least 5 d/week (adults) and 1 h moderate-intensity exercise/d (children). Evidence suggests a high prevalence of inactivity in adults, but whether or not inactivity is increasing cannot be assessed currently. Similarly, no definite conclusions are justified about either the levels of physical activity of children, or whether these are sufficient to maintain and promote health. Data to support the belief that activity levels in childhood track into adulthood are weak. Inactivity is associated with an increased risk of weight gain and obesity, but causality remains to be established. In children there is strong evidence to demonstrate a dose-response relationship between the prevalence and incidence of obesity and time spent viewing television. Future research should focus on refining methodology for physical activity assessment to make it more sensitive to the different dimensions and contexts of activity in different age-groups.

Environmental correlates of physical activity in youth - a review and update

Obesogenic environments are thought to underlie the increased obesity prevalence observed in youth during the past decades. Understanding the environmental factors that are associated with physical activity (PA) in youth is needed to better inform the development of effective intervention strategies attempting to halt the obesity epidemic. We conducted a systematic semi-quantitative review of 150 studies on environmental correlates of youth PA published in the past 25 years. The ANalysis Grid for Environments Linked to Obesity (ANGELO) framework was used to classify the environmental correlates studied. Most studies retrieved used cross-sectional designs and subjective measures of environmental factors and PA. Variables of the home and school environments were especially associated with children's PA. Most consistent positive correlates of PA were father's PA, time spent outdoors and school PA-related policies (in children), and support from significant others, mother's education level, family income, and non-vocational school attendance (in adolescents). Low crime incidence (in adolescents) was characteristic of the neighbourhood environment associated with higher PA. Convincing evidence of an important role for many other environmental factors was, however, not found. Further research should aim at longitudinal and intervention studies, and use more objective measures of PA and its potential (environmental) determinants.

Evaluation of a website-delivered computer-tailored intervention for increasing physical activity in the general population

OBJECTIVE

To examine if a website-delivered physical activity intervention, that provides participants with computer-tailored feedback, can improve physical activity in the general population.

METHODS

Healthy adults (n=434), recruited from parents and staff of 14 primary and secondary schools in Belgium in the spring of 2005, were allocated into one of two intervention groups (receiving intervention with or without repeated feedback) or a no-intervention control group. Physical activity-levels were self-reported at baseline and at 6 months (n=285), using a computerized long version of the International Physical Activity Questionnaire online. Repeated measures analysis of co-variances were used to examine differences between the three groups.

RESULTS

Intent-to-treat analysis showed significant time by group interaction effects in favor of both intervention groups compared with the control group. Significant increases were found for active transportation (+20, +24, +11 min/week respectively) and leisure-time physical activity (+26, +19, -4 min/week respectively); a significant decrease for minutes sitting on weekdays (-22, -34, +4 min/day respectively). No significant differences were found between both intervention groups.

CONCLUSION

A website-delivered intervention, including computer-tailoring, was able to increase physical activity when compared to a no-intervention control group. High drop-out rate and the low number of participants who received repeated feedback indicated that engagement and retention are important challenges in e-health studies.

Does timing and sequencing of transitions to adulthood make a difference? Stress, smoking, and physical activity among young Australian women

The major changes of the transition to adulthood are argued to be stressful, and health-related behaviors such as smoking and physical activity may be adopted, consolidated, or abandoned at this time. On the other hand, research has suggested that the normative transitions of emerging adulthood, although involving considerable change, may be associated with low stress because they are perceived as both positive and normal at this life stage. This article examines relations between the timing and sequencing of life transitions and stress and health-related behaviors, focusing on the transition to young adulthood among Australian women. A total of 853 women aged 22 to 27 provided information about the timing and sequencing of 6 life transitions: moving out of home, stopping full-time education, starting full-time work, having the first live-in relationship, marriage, and motherhood-and stress, smoking, and physical activity. Most had moved out of home, stopped full-time education, and started full-time work, but only 14% had undertaken all 6 transitions. Overall, 70% of participants had made transitions "in order." Overall, the findings suggest that the relations between timing and sequencing of transitions, and indicators of health, are moderate for smoking, but small for stress and for physical activity. These effects remained after controlling for socioeconomic status of the participants' families of origin. Matching current social norms for the timing and sequencing of life changes may be of less importance for women's well-being than is commonly believed. Although the significant relations between early or "out of order" transitions and smoking are of concern, the smaller relations with stress and with sedentariness suggest that such transitions may have limited negative consequences, and support the view that individuals are active in choosing the life path that is appropriate for them and their circumstances.

Five-year predictors of physical activity decline among adults in low-income communities: a prospective study

BACKGROUND

Obesity in North America is now endemic, and increased understanding of the determinants of physical inactivity is critical. This analysis identified predictors of declines in physical activity over 5 years among adults in low-income, inner-city neighbourhoods.

METHODS

Data on leisure time physical activity were collected in telephone interviews in 1992 and 1997 from 765 adults (47% of baseline respondents), as part of the evaluation of a community-based cardiovascular disease risk reduction program.

RESULTS

One-third of 527 participants who were physically active at baseline, were inactive in 1997. Predictors of becoming inactive included female sex (OR = 1.63 95% CI (1.09, 2.43)), older age (1.02 (1.01, 1.04)), higher BMI (1.57 (1.03, 2.40)), poor self-rated health (1.39 (1.05, 1.84)), lower self-efficacy for physical activity (1.46 (1.00, 2.14)), and not using a neighborhood facility for physical activity (1.61 (1.02, 2.14)).

CONCLUSION

These results highlight the fact that a variety of variables play a role in determining activity level, from demographic variables such as age and sex, to psychosocial and environmental variables. In addition, these results highlight the important role that other health-related variables may play in predicting physical activity level, in particular the observed association between baseline BMI and the increased risk of becoming inactive over time. Lastly, these results demonstrate the need for multi-component interventions in low-income communities, which target a range of issues, from psychosocial factors, to features of the physical environment.

Health-enhancing physical activity among Saudi adults using the International Physical Activity Questionnaire (IPAQ)

Objectives

To describe the physical activity profile of Saudi adults living in Riyadh, using the International Physical Activity Questionnaire (IPAQ) short-version telephone format.

Methods

Physical activity was assessed using the official Arabic short form of IPAQ, intended for use in telephone interview. The instrument asks for times spent in walking, moderate- and vigorous-intensity physical activity of at least 10 min duration. The sample consisted of 1616 Saudis, between 15 and 78 years of age, living in Riyadh. Participants were drawn from a list of names in the telephone book using a simple random method. Telephone interviews were administered during the spring of 2003 by trained male interviewers.

Results

The final sample size was 1064 Saudi males and females (response rate of 66%), with males comprising about 66% of the respondents. Over 43% of Saudis did not participate in any type of moderate-intensity physical activity lasting for at least 10 min. More than 72% of the sample did not engage in any type of vigorous-intensity physical activity lasting for at least 10 min. The proportion of Saudis who walked for 150 min or more per week was 33.3%. Females were engaged more in moderate physical activity than males, whereas males participated more in vigorous activity compared with females. Activity levels did not show significant relationships with education level or job hours per week. Based on the three activity categories established by IPAQ, 40.6% of Saudis were inactive, 34.3% were minimally active and 25.1% were physically active. Physical inactivity increased with advancing age.

Conclusion

The data suggest that the prevalence of physical inactivity among Saudis adults is relatively high. Efforts are needed to encourage Saudis to be more physically active, with the goal of increasing the proportion of Saudis engaging in health-enhancing physical activity.

The effect of the holiday season on body weight and composition in college students

Background

With the rapid increase in obesity rates, determining critical periods for weight gain and the effects of changes in fat mass is imperative. The purpose of this study was to examine changes in body weight and composition over the holiday season (Thanksgiving through New Year's) in male and female college students.

Methods

Subjects completed three visits: the first occurred within 2 weeks prior to Thanksgiving, the second occurred within 5 to 7 days following Thanksgiving, and the third occurred within 10 days following New Year's Day. A total of 82 healthy male and female college age subjects participated. Body composition by dual energy x-ray absorptiometry (DXA) was assessed at visits 1 and 3 while body weight was assessed at all three visits.

Results

Average body weight remained relatively unchanged from pre-Thanksgiving to post-New Year's (71.3 ± 14 kg vs. 71.2 ± 15 kg; P = 0.71) and, in fact, a subset of normal weight subjects lost a significant amount of body weight. However, percent body fat (25.9 ± 9 %fat vs. 27.0 ± 9 %fat; P < 0.01) and fat mass (18.3 ± 8 kg and 19.1 ± 8 kg; P < 0.01) significantly increased from pre-Thanksgiving to post-New Year's while fat-free mass (48.7 ± 12 kg and 48.3 ± 11 kg; P = 0.08) was not significantly different than the post-New Year's. A significant positive relationship (P < 0.001) between the change in BMI and percent fat, total fat mass, total fat free mass, and trunk fat mass for the pre-Thanksgiving and post-New Year's visits were found. The same significant positive relationships (P < 0.001) were also observed between the change in body weight and percent fat, total fat mass, total fat free mass, and trunk fat mass.

Conclusion

Despite the fact that body weight remained unchanged over the course of the holiday season, a significant increase in %body fat and fat mass was observed. With recent evidence showing marked morbidity and mortality to be associated with increased body fat (particularly abdominal adiposity), results from this study suggest body weight alone may underestimate the potentially deleterious effects of the holiday season.

Genetic influences on exercise participation in 37,051 twin pairs from seven countries

BACKGROUND

A sedentary lifestyle remains a major threat to health in contemporary societies. To get more insight in the relative contribution of genetic and environmental influences on individual differences in exercise participation, twin samples from seven countries participating in the GenomEUtwin project were used.

METHODOLOGY

Self-reported data on leisure time exercise behavior from Australia, Denmark, Finland, Norway, The Netherlands, Sweden and United Kingdom were used to create a comparable index of exercise participation in each country (60 minutes weekly at a minimum intensity of four metabolic equivalents).

PRINCIPAL FINDINGS

Modest geographical variation in exercise participation was revealed in 85,198 subjects, aged 19-40 years. Modeling of monozygotic and dizygotic twin resemblance showed that genetic effects play an important role in explaining individual differences in exercise participation in each country. Shared environmental effects played no role except for Norwegian males. Heritability of exercise participation in males and females was similar and ranged from 48% to 71% (excluding Norwegian males).

CONCLUSIONS

Genetic variation is important in individual exercise behavior and may involve genes influencing the acute mood effects of exercise, high exercise ability, high weight loss ability, and personality. This collaborative study suggests that attempts to find genes influencing exercise participation can pool exercise data across multiple countries and different instruments.

Trends in physical activity and sedentary behaviour in adolescence: ethnic and socioeconomic differences

OBJECTIVE

To assess developmental trends in physical activity and sedentary behaviour in British adolescents in relation to sex, ethnicity and socioeconomic status (SES).

DESIGN

A 5-year longitudinal study of a diverse cohort of students aged 11-12 years at baseline in 1999.

SETTING

36 London schools sampled using a stratified random sampling procedure.

PARTICIPANTS

A total of 5863 students categorised as white, black or Asian, and stratified for SES using the Townsend Index.

MAIN OUTCOME MEASURES

Number of days per week of vigorous activity leading to sweating and breathing hard. Hours of sedentary behaviour, including watching television and playing video games. Data were analysed using multilevel, linear, mixed models.

RESULTS

Marked reductions in physical activity and increases in sedentary behaviour were noticed between ages 11-12 and 15-16 years. Boys were more active than girls, and the decline in physical activity was greater in girls (46% reduction) than in boys (23%). Asian students were less active than whites, and this was also true of black girls but not boys. Black students were more sedentary than white students. Levels of sedentary behaviour were greater in respondents from lower SES. Most differences between ethnic and SES groups were present at age 11 years, and did not evolve over the teenage years.

CONCLUSIONS

Physical activity declines and sedentary behaviour becomes more common during adolescence. Ethnic and SES differences are observed in physical activity and sedentary behaviour in British youth that anticipate adult variations in adiposity and cardiovascular disease risk. These are largely established by age 11-12 years, so reversing these patterns requires earlier intervention.

Ten-year follow-up of the Cretan Health and Nutrition Education Program on children's physical activity levels

OBJECTIVE

To examine the effect of a 6-year school-based intervention program, implemented on the island of Crete, on children's physical activity levels at the end of the intervention and at a follow-up examination 4 years after program's cessation.

METHODS

Subjects with complete moderate to vigorous physical activity (MVPA) data at baseline, post-intervention and follow-up examination (Academic years 1992-1993, 1997-1998 and 2001-2002 respectively) were included in the analysis [n = 425: Intervention Group (IG): 238; Control Group (CG): 187]. Repeated measures analysis of variance and logistic regression analysis were mainly performed to evaluate the tested hypothesis.

RESULTS

Subject's mean age was 6.3, 11.5 and 15.3 years at baseline, post-intervention and follow-up examination, respectively. MVPA levels were significantly higher for males in the IG than CG at post-intervention (510.2 +/- 404.6 vs. 350.7 +/- 308.0 min/week, P < 0.001) and follow-up (112.3 +/- 78.9 vs. 96.3 +/- 67.0 min/week, P = 0.029). Furthermore, males in the IG were 2.3 (P = 0.011) and 2.1 (P = 0.041) times more likely to meet recommendations for physical activity at the post-intervention and the follow-up examination, respectively, than the CG. No significant findings were observed for females.

CONCLUSION

The current study indicates a favorable effect of the intervention on boys' physical activity levels, which was maintained 4 years after the end of the program.

A systematic review of randomized trials on the effectiveness of computer-tailored education on physical activity and dietary behaviors

BACKGROUND

Although computer-tailored promotion of dietary change and physical activity has been identified as a promising intervention strategy, there is a need for a more systematic evaluation of the evidence.

PURPOSE

This study systematically reviews the scientific literature on computer-tailored physical activity and nutrition education.

METHODS

Intervention studies published from 1965 up to September 2004 were identified through a structured search in PubMed, PsycInfo, and Web of Science and an examination of reference lists of relevant publications. Studies were included that applied a pretest-posttest randomized-controlled trial design, were aimed at primary prevention among adults, used computer-tailored interventions to change physical activity and dietary behaviors, and were published in English. The search resulted in 30 publications-11 on physical activity behaviors and 26 on nutrition behaviors, some studies investigated multiple behaviors.

RESULTS

Three of 11 of the physical activity studies and 20 of 26 of the nutrition studies found significant effects of the tailored interventions. The evidence was most consistent for tailored interventions on fat reduction.

CONCLUSIONS

Overall, there seems to be potential for the application of computer tailoring for promoting healthy diets, but more research is needed to test computer-tailored interventions against other state-of-the-art intervention techniques and to identify the mechanisms underlying successful computer tailoring.