The effects of a 2-year physical education program (SPARK) on physical activity and fitness in elementary school students. Sports, Play and Active Recreation for Kids

OBJECTIVES

This study evaluated a health-related physical education program for fourth- and fifth-grade students designed to increase physical activity during physical education classes and outside of school.

METHODS

Seven schools were assigned to three conditions in a quasi-experimental design. Health-related physical education was taught by physical education specialists or trained classroom teachers. Students from these classes were compared with those in control classes. Analyses were conducted on 955 students with complete data.

RESULTS

Students spent more minutes per week being physically active in specialist-led (40 min) and teacher-led (33 min) physical education classes than in control classes (18 min; P < .001). After 2 years, girls in the specialist-led condition were superior to girls in the control condition on abdominal strength and endurance (P < .001) and cardiorespiratory endurance (P < .001). There were no effects on physical activity outside of school.

CONCLUSIONS

A health-related physical education curriculum can provide students with substantially more physical activity during physical education classes. Improved physical education classes can potentially benefit 97% of elementary school students.

Factors parents use in selecting play spaces for young children

BACKGROUND

The amount of time children spend in play spaces (ie, physical locations that are appropriate for children's physical activity) near their homes is correlated with their level of physical activity.

OBJECTIVE

To examine factors used in parents' decisions about the selection of play spaces for their children.

SUBJECTS

Parents (primarily mothers) of 178 Mexican American and 122 white children who were a mean age of 4.9 years old at the first measurement.

MEASURES

In individual interviews, parents rated 24 factors on their importance in selecting for their children a play space that is away from their home or yard. Decision factors were rated from 1 (ie, not important at all) to 5 (ie, very important).

RESULTS

The most important factors, with ratings ranging from 4.8 to 4.2, were safety and availability of toilets, drinking water, lighting, and shade. Mexican American parents rated 8 of 24 items significantly higher than did white parents, including lighted at night, organized activities, play supplies, and drinking water. White parents rated 5 of 24 items significantly higher than did Mexican American parents, including distance from home, cost of admission, and child's friends go there. The rated importance of 7 of 24 items increased during 1 year, including play supplies, drinking water, distance from home, and parents' friends or relatives go there.

CONCLUSIONS

These results indicate that parents can identify factors they use in selecting places for their young children to play, and selection factors differ somewhat by ethnicity or socioeconomic status. Further studies are needed to determine whether improvements on the most important selection factors might be effective in increasing the use of play spaces by children and their parents. Clinicians may be able to use the most highly rated decision factors to help parents assess the acceptability of play spaces in their areas.

School physical education: effect of the Child and Adolescent Trial for Cardiovascular Health

BACKGROUND

Physical inactivity is a risk behavior for cardiovascular and other diseases. Schools can promote public health objectives by increasing physical activity among youth.

METHODS

The Child and Adolescent Trial for Cardiovascular Health (CATCH) was a multicenter, randomized trial to test the effectiveness of a cardiovascular health promotion program in 96 public schools in four states. A major component of CATCH was an innovative, health-related physical education (P+) program. For 2.5 years, randomly assigned schools received a standardized PE intervention, including curriculum, staff development, and follow-up.

RESULTS

Systematic analysis of 2,096 PE lessons indicated students engaged in more moderate-to-vigorous physical activity (MVPA) in intervention than in control schools (P = 0.002). MVPA during lessons in intervention schools increased from 37.4% at baseline to 51.9%, thereby meeting the established Year 2000 objective of 50%. Intervention children reported 12 more min of daily vigorous physical activity (P = 0.003) and ran 18.6 yards more than control children on a 9-min run test of fitness (P = 0.21).

CONCLUSIONS

The implementation of a standardized curriculum and staff development program increased children's MVPA in existing school PE classes in four geographic and ethnically diverse communities. CATCH PE provides a tested model for improving physical education in American schools.

Cardiovascular risk factors among children after a 2 1/2-year intervention-The CATCH Study

BACKGROUND

Cardiovascular risk factors and related behaviors begin during youth.

METHODS

As part of the Child and Adolescent Trial for Cardiovascular Health, 4,019 children from four states and representing multiple ethnic groups were measured for selected risk factors both at baseline and after 2(1/2) years of intervention. Common protocols were used for both examinations at the four sites.

RESULTS

Overall, changes in obesity, blood pressure, and serum lipids in the intervention group, compared with the control group, were not statistically significant. Total cholesterol, the primary physiologic outcome measure, decreased by 1.3 mg/dl over time in the intervention group and by 0.9 mg/dl (P > 0.05) in the control group. Different risk factor patterns for boys and girls and among three ethnic groups were noted.

CONCLUSIONS

Although the school-based program effected significant institutional changes in food service and physical education class and although the children made significant changes in eating and physical activity behaviors, these did not translate to significant changes in risk factors at these ages. These behavioral changes, however, if sustained into adulthood, have the potential to influence cardiovascular risk reduction.

Children's activity levels and lesson context during third-grade physical education

Little is known about children's activity levels during physical education classes and how they relate to the national health objectives for the year 2000 (U.S. Public Health Service, 1991). We systematically observed students' physical activity and associated variables in 293 third-grade physical education lessons in 95 schools in 4 Child and Adolescent Trial for Cardiovascular Health (CATCH) centers in California, Louisiana, Minnesota, and Texas. The influence of independent variables was assessed simultaneously by analysis of variance. Significant differences among study centers were evidenced for both physical activity and lesson context variables. Additionally, there were differences among variables for lesson location and teacher specialty, but not for teacher gender. Boys were more active than girls, but only during free play opportunities. The findings have widespread implications for educators responsible for developing and implementing health-related physical education programs, as well as for designing and conducting staff development.

Variability and tracking of physical activity over 2 yr in young children

The purpose of this study was to examine tracking of physical activity at home and recess in young children. Three hundred fifty-one Mexican-American and Anglo-American children entered the study (mean age = 4.4 yr), and 83% completed 2 yr of measurement. Physical activity was directly observed on 10 d over 2 yr. Measurement waves occurred every 6 months, and each wave consisted of 2 d of observation within 1 wk. Children were observed for 60 min at home on a weekday evening and up to 30 min during recess at preschool or school. Maximum likelihood procedures using a linear mixed-effects model indicated that most of the variance in home and recess physical activity was accounted for by short-term/weekly factors. Tracking of physical activity accounted for 15% of the total variance at home and 8% at recess. Pearson correlations for physical activity over time were higher at home than at recess. Tracking of home physical activity was r = 0.15 when single days were correlated and r = 0.36 when the means of 4 d were correlated. There was a small, but detectable, stable component of physical activity in young children, at least at home.

Improved accumulation and activity of ribozymes expressed from a tRNA-based RNA polymerase III promoter

RNA polymerase III (pol III) transcripts are abundant in all cells. Therefore, pol III promoters may be ideal for expressing high levels of exogenous RNAs, such as antisense RNAs, decoy RNAs and ribozymes, in many different cell types. We have improved accumulation of recombinant RNAs expressed from a human meti tRNA-derived pol III promoter > 100-fold by modifying the 3' terminus of the transcripts to hybridize to the 5' terminus. This terminal duplex includes the 8 nt leader sequence present in the primary wild-type meti tRNA transcript that is normally removed during processing to the mature tRNA. Expression of an anti-HIV ribozyme was analyzed in cells stably transduced with retroviral vectors encoding pol III transcription units containing this modification. High accumulation of recombinant pol III ribozyme transcripts was observed in all cell lines tested. Due to the enhanced transcript accumulation, ribozyme cleavage activity was readily detectable in total RNA extracted from stably transduced human T cell lines. One pol III transcription unit, termed 'TRZ', was optimized further for ribozyme cleavage activity. The improved pol III transcription units reported here may be useful for expressing a variety of functional and therapeutic RNAs.

CATCH: physical activity process evaluation in a multicenter trial

This paper presents the process evaluation model for the physical activity intervention component of the Child and Adolescent Trial for Cardiovascular Health (CATCH) and describes the major procedures used to monitor CATCH PE, the physical education intervention. The paper focuses on CATCH PE teacher training and in-service support as well as on the curriculum implementation. Monitoring training and support included assessing the in-service training workshops and the follow-up on-site assistance provided by staff. Monitoring the implementation included assessing the quantity and quality of CATCH PE instruction in terms of student physical activity engagement and lesson context, the fidelity of the curricular implementation, and the opportunities for other physical activity by children throughout the school day.

Localization of the squalene synthase gene (FDFT1) to human chromosome 8p22-p23.1

Recently, we reported the isolation of a cDNA encoding the human enzyme squalene synthase, the first step of sterol biosynthesis uniquely committed to synthesis of cholesterol (6). As such, it is likely that this enzyme occupies a critical regulatory position in the synthesis of cholesterol. As part of continuing studies of the role of this gene in cellular metabolism, we undertook the mapping of this gene on the human chromosomes. To localize the gene, we have first isolated a yeast artificial chromosome (YAC) containing the squalene synthase gene. We then used fluorescence in situ hybridization (FISH) with yeast DNA containing the YAC to localize the gene to chromosome 8. Assignment to human chromosome 8 was confirmed by polymerase chain reaction analysis of a somatic cell hybrid containing human chromosome 8. Use of a somatic cell hybrid regional mapping panel dividing chromosome 8 into several fragments localized the gene to 8p21-pter. Fractional length analysis of the FISH mapping placed the signal generated with this YAC at 8p22-p23.1.

Correlates of physical activity at home in Mexican-American and Anglo-American preschool children

Twenty-two potential correlates of children's physical activity were examined. Two hundred and one Mexican-American and 146 Anglo-American families with 4-year-old children were studied. Children's physical activity was directly observed in the evening at home on 4 visits for 1 hr each time. Anglo-American children and male children were found to be more active. Demographic variables explained 11% of the variance in children's physical activity. After adjusting for demographics, 3 children's variables and 6 social-family variables did not account for significantly more variance. Five environmental variables accounted for 11% additional variance. Variables observed concurrently with physical activity, such as time spent outdoors and prompts to be active, were highly associated with children's physical activity.

Project SPARK. Effects of physical education on adiposity in children

Project SPARK evaluates multiple effects of a health-related physical education (PE) program for elementary school students. Seven schools were randomly assigned to one of three conditions: usual PE or control, trained classroom teachers, or PE specialists. The intervention was implemented throughout the fourth and fifth grades. Data are available from one cohort of 550 children who were measured in the fall and spring of both grades. Adiposity was assessed by triceps and calf skinfolds, and body mass index (BMI) was also measured. Data at each measurement point were analyzed by ANOVAs, covarying for baseline values. At no measurement point were there significant group differences in total skinfold. At both fifth grade measurement points for boys and girls, however, there was a trend for the control group to have higher skinfold values than the two intervention groups. At the final measure, the difference between the highest and lowest groups was about 3 mm for girls and 2 mm for boys. BMIs were significantly lower at some measurement points for boys and girls, but this could be due to increased lean body mass in intervention students. After two years, there was a trend for the children exposed to the PE intervention to have lower levels of body fat, but the differences were not significant.

Correlates of physical activity at home in Mexican-American and Anglo-American preschool children

Twenty-two potential correlates of children's physical activity were examined. Two hundred and one Mexican-American and 146 Anglo-American families with 4-year-old children were studied. Children's physical activity was directly observed in the evening at home on 4 visits for 1 hr each time. Anglo-American children and male children were found to be more active. Demographic variables explained 11% of the variance in children's physical activity. After adjusting for demographics, 3 children's variables and 6 social-family variables did not account for significantly more variance. Five environmental variables accounted for 11% additional variance. Variables observed concurrently with physical activity, such as time spent outdoors and prompts to be active, were highly associated with children's physical activity.

Habitual physical activity and health-related physical fitness in fourth-grade children

OBJECTIVE

To examine the relationship between habitual physical activity and components of health-related physical fitness in children.

DESIGN

Cross-sectional survey with correlational analysis.

SETTING

Seven public elementary schools in a suburban southern California city.

PARTICIPANTS

Five hundred twenty-eight healthy fourth-grade children (274 boys and 254 girls), 85% of whom were non-Hispanic whites. Ninety-eight percent of eligible students participated.

INTERVENTIONS

None.

MEASUREMENTS/MAIN RESULTS

Results of six measures of physical activity in children (monitoring by accelerometer, parent report, and child self-reports of weekday activity, weekend activity, and summer involvement in activity classes and youth sports) were combined in a physical activity index. This index of habitual physical activity was examined in relation to measures of five components of health-related fitness: the mile run, skin-fold tests, pull-ups, sit-ups, and the sit-and-reach test. The physical activity index was significantly associated with all five fitness components. The canonical correlation was .29.

CONCLUSION

Active children appear to engage in a sufficient variety of activities to enhance multiple components of health-related fitness.

Transcriptional regulation by lovastatin and 25-hydroxycholesterol in HepG2 cells and molecular cloning and expression of the cDNA for the human hepatic squalene synthase

Primers, based on the cDNA nucleotide sequences for rat hepatic squalene synthase (EC 2.5.1.21) (McKenzie, T.L., Jiang, G., Straubhaar, J.R., Conrad, D., and Shechter, I. (1992) J. Biol. Chem. 267, 21368-21374), were synthesized and used for the amplification and sequencing of a 1672-base pair (bp) cDNA for the human hepatic squalene synthase (HSS) from human hepatic RNA. An open reading frame of 1251 bp encoding 417 amino acids (M(r) = 48,200) was detected for HSS. We have constructed a pHSS 1286 expression vector by molecular cloning of a 1286-bp cDNA, that includes sequences of the entire coding region for HSS, into pBluescript. Expression in Escherichia coli of a functional, full-length HSS was confirmed by immunoblot analysis and enzymatic activity. Northern blot analyses of poly(A+) RNA obtained from the human hepatoma cell line HepG2 show three distinct size classes of mRNA for HSS. 1.4-, 1.6- and 2.1-kilobase mRNA were observed. The relative abundance is in the order 1.6 > 1.4 > 2.1 and did not change when the cells were grown in the presence of 25-hydroxycholesterol or lovastatin. The ratio between the level of HSS mRNA in cells grown in the absence and presence of 5 micrograms/ml 25-hydroxycholesterol varies between 8- and 16-fold. This lowering of the mRNA level was observed when the cells were grown in 10% of either full serum or lipid-depleted serum. A 2.7- and 4.0-fold increase of HSS mRNA was observed when HepG2 cells were grown in the presence of 5 micrograms/ml lovastatin in lipid-depleted or full serum, respectively. These studies show that HSS exhibit a relatively high level of transcriptional regulation in response to 25-hydroxycholesterol regardless of the presence of cholesterol in the growth media.

Effects of a curriculum and inservice program on the quantity and quality of elementary physical education classes

The primary responsibility for engaging children in opportunities to be physically active and learn physical skills rests with school physical education. This study evaluated the effects of a combined health-related curriculum and inservice program on the quantity and quality of elementary school physical education lessons. Seven schools (N = 28 fourth-grade classes) in one district were randomly assigned to one of three conditions: 10 classes were taught in their usual manner by classroom teachers (Control [CO]); 10 classes were taught by trained classroom teachers (TT) who received inservice training and follow-up consultations; and 8 classes were taught by physical education specialists (PES) hired by the research project. Student activity level, curriculum context, and teacher behavior were directly observed and coded during a sample of 112 lessons over an 8-month period. Results indicated significant differences in both the frequency and mean length of classes (PES, 26.7 min; TT, 23.4 min; CO, 18.9 min). Additionally, the curriculum and inservice program equipped trained classroom teachers to provide significantly better classes than were provided by controls in terms of student activity engagement, lesson context, and active instructional behavior, though their classes did not match the quality of those taught by the physical education specialists. This study is unique in its use of direct observation of lessons to assess a curriculum and inservice intervention.

Parental behavior in relation to physical activity and fitness in 9-year-old children

OBJECTIVE

To examine the relationship between parental behaviors and physical activity and fitness in elementary school-aged children.

DESIGN

Cross-sectional survey of students and parents.

SETTING

Seven public elementary schools in a suburban southern California city.

PARTICIPANTS

One hundred forty-eight fourth-grade girls and 149 fourth-grade boys and their parents. Eighty-four percent were white.

INTERVENTIONS

None.

MEASUREMENTS/MAIN RESULTS

Children's physical activity was indicated by self-report, data obtained from a monitor (accelerometer), and results of the mile run/walk. Multiple regression analysis, controlling for ethnicity and body mass index, was conducted separately for girls and boys to explain variation in child activity and fitness. Parents' reported physical activity was not associated with child activity or fitness. However, availability of transportation by parents to sport and fitness activities was significant (or nearly so) in two regressions for boys and in one regression for girls. Parents who played with their children had more active boys, based on self-report, but verbal encouragement to be active was not significant in any model.

CONCLUSION

The parental role as gatekeeper of access to activity and sport facilities deserves further study.

Molecular cloning, expression, and characterization of the cDNA for the rat hepatic squalene synthase

Amino acid sequence information was obtained for the NH2 terminus, and for endogenous peptides generated by trypsin digestion, of a purified, truncated form of rat hepatic squalene synthase (RSS, EC 2.5.1.21) (Shechter, I., Klinger, E., Rucker, M. L., Engstrom, R. G., Spirito, J. A., Islam, M. A., Boettcher, B. R., and Weinstein, D. B. (1992) J. Biol. Chem. 267, 8628-8635). Degenerate primers, based on the amino acid sequences, were synthesized and used for the amplification and sequencing of a 1708-base pair (bp) cDNA for RSS from the rat hepatoma cell line H35. An open reading frame of 1248 bp encoding 416 amino acids (M(r) = 48,103) was detected for RSS. We have constructed a pRSS1327 expression vector by molecular cloning of a 1327-bp cDNA, which includes sequences of the entire coding region for RSS, into pBluescript. Expression in Escherichia coli of a functional, full-length RSS was confirmed by immunoblot analysis and enzymatic activity. We present and evaluate a model for the secondary structure of RSS and its possible membrane orientation. The model predicts a 315-residue domain at the center of the protein that contains the catalytic site and is released in a soluble form by partial proteolysis. The 33-residue NH2-terminal and 98-residue COOH-terminal sections are not involved in catalysis. Sequence analysis of the catalytic domain of RSS indicate three regions with high homology to sequences in a number of functionally distinct proteins that utilize polyprenyl diphosphate substrates.

Anglo- and Mexican-American preschoolers at home and at recess: activity patterns and environmental influences

Habitual physical activity in children is related to physical fitness and appears to mediate cardiovascular disease (CVD) risk factors. We studied the physical activity patterns and associated variables of a large bi-ethnic cohort of 4-year-old children from low to middle socioeconomic families. Trained observers coded the behavior of 351 children (150 Anglo-American, 201 Mexican-American; 182 boys, 169 girls) during two 60-minute home visits and two unstructured recesses lasting up to 30 minutes each at 63 different preschools. Findings indicated that although children were much less active at home, there were low but significant correlations between their activity patterns at home and during recess (r = .13). Children who had activity-promoting toys at home also tended to have them available during preschool recess (r = .20). Ethnic differences were evident for both activity and environmental variables. Mexican-American children were less active than Anglo children at home (p less than .002) and during recess (p less than .03), thus adding to the adult literature that has found Mexican-Americans to be less active than Anglos, and supporting to the notion that physical activity life-style habits may be established in early childhood. In both settings, Mexican-American children spent more time in presence of adults (home, p less than .04; recess, p less than .03) and had access to fewer active toys (home, p less than .001; recess, p less than .05). Gender differences were also evident for both activity and environmental variables.(ABSTRACT TRUNCATED AT 250 WORDS)

BEACHES: an observational system for assessing children's eating and physical activity behaviors and associated events

An integrated system for coding direct observations of children's dietary and physical activity behaviors was developed. Associated environmental events were also coded, including physical location, antecedents, and consequences. To assess the instrument's reliability and validity, 42 children, aged 4 to 8 years, were observed for 8 consecutive weeks at home and at school. Results indicated that four 60-min observations at home produced relatively stable estimates for most of the 10 dimensions. Interobserver reliabilities during live and videotaped observations were high, with the exception of "consequences" categories that occurred in less than 1% of observed intervals. Evidence of validity was provided by findings that antecedents were associated with respective dietary and physical activity behaviors. The five physical activity categories were validated by heartrate monitoring in a second study. The Behaviors of Eating and Activity for Children's Health Evaluation System is appropriate for studying influences on diet and physical activity in children in a variety of settings.

Stability of systolic blood pressure reactivity to exercise in young children

Blood pressure reactivity to stress in childhood has predicted development of hypertension 45 years later, so it is important to understand the characteristics of blood pressure reactivity in childhood. The present study assessed the 1-week and 6-month stability of systolic blood pressure reactivity to a 40-meter run stressor in preschool children. Sixty-three low-income children (mean age, 3.9 years) were assessed on four different days over a 6-month period. One-week stability (r = 0.39 to 0.50) and 6-month stability (r = 0.56) of reactive systolic blood pressure levels were highly significant. Reactive systolic blood pressure level was more stable than resting systolic or diastolic blood pressure in this sample. Sex, body mass index, family cardiovascular disease history, and child Type A behavior all were unrelated to systolic blood pressure reactivity. Systolic blood pressure reactivity to exercise appears to be an enduring characteristic that emerges in early childhood.

Direct observation of physical activity and dietary behaviors in a structured environment: effects of a family-based health promotion program

The effects of cardiovascular risk reduction are typically assessed by self-reported behavior change and physiological outcomes. There is a need to enhance evaluation protocols by including direct observation measures of targeted health behaviors. To improve the evaluation of a family-based diet and physical activity change program, families were observed during a planned visit to the San Diego Zoo. This standardized environment afforded many options for dietary intake and physical activity. Thirty families who had participated in a 1-year intervention program and 30 control families were observed. Caucasian and Mexican-American families were equally represented. Observations in this standard environment discriminated between intervention and control families, and the findings indicated that intervention effects generalized to this novel setting. Intervention families consumed fewer calories, ate less sodium, and walked further than did control families. Ethnic differences were noted.

Family variables and physical activity in preschool children

Correlates of the physical activity habits of preschool children were studied in a multiethnic sample. Physical activity levels of 33 low-income children were observed systematically during free-play periods at preschool. Children spent 58% of free-play time in sedentary activities (e.g., sitting), and were vigorously active only 11% of the time. Independent variables studied were child body mass index (BMI), teacher-rated Type A behavior, and parent-reported mother BMI, father BMI, parent vigorous activity, and family cardiovascular disease (CVD) risk. The multiple regression of moderate-intensity activity was significant, with family CVD risk, parent vigorous activity, and father BMI accounting for significant amounts of variance. The results suggest that the effects of parental role modeling on child physical activity levels may extend to free-play settings far beyond the confines of the home environment.

Effects of self-recording on attendance and performance in a competitive swimming training environment

Swimmers' attendance at training and work rates were described by their coaches as being poor and irregular. Reinforcement contingencies were developed to remedy these unsatisfactory conditions. Two experiments were conducted. A multiple baseline design verified the effects of publicly marking attendance at practice as a sufficient solution for reducing absenteeism, tardiness, and leaving early. Follow-up analyses showed this contingency to have lasting effects. In the second experiment, a reversal design was used to assess the effects of employing program boards as a means of increasing work output during practice. Work rates in eight selected swimmers were elevated by an average of 27.1% when the boards were instituted. Follow-up evaluations showed that the use of the program boards had lasting effects. Publicly checking the completion of each training unit of work changed the nature of the swimming environment to produce a more productive use of time. The role of the coach was subsequently changed as less time was spent in directing and supervising behaviors.