Biomedical subjects

Russell R Pate

Publications and source records attributed to Russell R Pate.

46 records · Page 3Linked to original sources

PubMed2003

Effects of short-term exercise training on plasminogen activator inhibitor (PAI-1).

PURPOSE: To observe the effects of exercise training on plasminogen activator inhibitor, type-1 (PAI-1), tissue plasminogen activator (tPA), and associated metabolic variables in sedentary men and women. METHODS: A randomized, controlled experimental design was used to examine the influence of 10 d of moderate-intensity exercise training on measures of fibrinolysis. Sixteen men and 16 women between the ages of 50 and 70 yr were randomly assigned to exercise (EX) and control groups (CON) that were balanced for gender and hormone replacement therapy. Blood samples were collected on days 1, 2, 11, and 12 for measurement of plasma PAI-1, tPA, insulin, glucose, and triglyceride. Subjects in EX performed 50 min of treadmill walking at an intensity corresponding to 65% of heart rate reserve each day for 10 consecutive days. RESULTS: There were no significant changes in PAI-1, tPA, or associated metabolic variables between EX and CON during the intervention period. Within EX subjects, those with higher body fatness had a significant decrease in insulin and triglyceride compared with those with lower body fatness. However, no changes in fibrinolytic measures were observed within these subgroups. CONCLUSIONS: Short-term exercise training does not change PAI-1 levels in normal, asymptomatic men and women. In addition, modest decreases in insulin and triglyceride in individuals with elevated body fatness do not result in changes in PAI-1 after short-term training. It appears likely that decreases in PAI-1 with exercise training require decreases in adiposity and/or marked changes in metabolic variables.

Aged↗

PubMed2002

Psychosocial mediators of physical activity behavior among adults and children.

BACKGROUND: Researchers examining theory-based, physical activity (PA) interventions postulate that interventions are effective by changing theoretical constructs hypothesized to mediate the relationship between the intervention and PA behavior. Research indicates that PA interventions are effective for increasing PA behavior. However, whether effective interventions are due to predicted changes in theoretical constructs remains poorly understood. METHODS: Studies that examined theoretical constructs (i.e., mediators) in PA interventions of adults or children, which used experimental designs and met other criteria for evaluating mediation, were collected via literature searches, personal searches of files, and personal communications. Only studies examining the direct effect of the intervention on the hypothesized mediator were considered relevant for this study. RESULTS: Based on our criteria, the adult literature search yielded ten studies and the child literature search yielded two studies. The most common mediators examined included behavioral processes of change, cognitive processes of change, self-efficacy, decisional balance, social support, and enjoyment. Research indicates that behavioral processes are likely mediators. There was some support for the importance of self-efficacy as a mediator. CONCLUSIONS: Few studies have used statistically recommended methods to examine mediators in PA intervention studies. Therefore, definitive conclusions about the importance of the mediators reviewed are not possible at this time. Additional PA mediator-intervention studies using recommended statistical methods are necessary to truly test if theory-based PA interventions are effective due to predicted changes in theoretical constructs.

Adolescent↗

PubMed2002

Compliance with physical activity guidelines: prevalence in a population of children and youth.

PURPOSE: To use objective monitoring of physical activity to determine the percentages of children and youth in a population that met physical activity guidelines. METHODS: A total of 375 students in grades 1-12 wore an accelerometer (CSA 7164) for seven consecutive days. Bouts of continuous activity and accumulation of minutes spent in physical activity at various intensities were calculated to determine how many students met three physical activity guidelines. RESULTS: Over 90% of students met Healthy People 2010, Objective 22.6 and nearly 70% met the United Kingdom Expert Consensus Group guideline, both of which recommend daily accumulation of moderate physical activity. Less than 3% met Healthy People 2010, Objective 22.7, which calls for bouts of continuous vigorous physical activity. For the United Kingdom Expert Consensus Group guideline, compliance decreased markedly with age, but gender differences were not statistically significant. CONCLUSIONS: Prevalence estimates for compliance with national physical activity guidelines varied markedly for the three guidelines examined. Objective monitoring of physical activity in youth appears to be feasible and may provide more accurate prevalence rates than self-report measures.

Activities of Daily Living↗

PubMed2002

Psychosocial correlates of physical activity in white and African-American girls.

PURPOSE: To evaluate the relative utility of the Theory of Reasoned Action (TRA) and the Theory of Planned Behavior (TPB) in explaining intentions and physical activity behavior in white and African-American eighth-grade girls. METHODS: One-thousand-thirty white and 1.114 African-American eighth-grade girls (mean age 13.6 +/- 0.7 years) from 31 middle schools in South Carolina completed a 3-day physical activity recall and a questionnaire assessing attitudes, subjective norms, perceived behavioral control, self-efficacy, and intentions related to regular participation in moderate-to-vigorous physical activity (MVPA). RESULTS: Among Whites, 17% of the variance in intentions was contributed by subjective norms and attitude, with intentions accounting for 8% of the variance in MVPA. The addition of perceived behavioral control and self-efficacy to the TRA significantly improved the prediction of intentions and MVPA accounting for 40% and 10% of the variance, respectively. Among African-Americans, subjective norms and attitude accounted for 13% of the variance in intentions, with intentions accounting for only 3% of the variance in MVPA. The addition of perceived behavioral control and self-efficacy to the TRA significantly improved the prediction of intentions and MVPA accounting for 28% and 5% of the variance, respectively. CONCLUSIONS: The results provided limited empirical support for the TPB among white adolescent girls; however, our findings suggest that the planned behavior framework has limited utility among African-American adolescent girls. The relatively weak link between intentions and MVPA observed in both population groups suggest that constructs external to the TPB may be more important mediators of physical activity behavior in adolescent girls.

Adolescent↗

PubMed2002

Physical activity and the metabolic syndrome in a tri-ethnic sample of women.

OBJECTIVE: To determine the association of moderate-intensity physical activity (PA), vigorous-intensity PA, and maximal treadmill duration with the metabolic syndrome among African-American (n = 49), Native-American (n = 46), and white (n = 51) women (ages, 40 to 83 years), enrolled in the Cross-Cultural Activity Participation Study. RESEARCH METHODS AND PROCEDURES: The metabolic syndrome was defined as three or more of the following risk factors: waist circumference >88 cm, blood pressure > or =130/85 mm Hg, fasting glucose > or =110 mg/dL, hypertriglyceridemia (> or =150 mg/dL), and high-density lipoprotein-cholesterol <50 mg/dL. PA was determined from detailed PA records that included all PA performed during two consecutive 4-day periods. Maximal treadmill duration was determined from a graded exercise test. Women were categorized into quartiles of moderate-intensity PA, vigorous-intensity PA, and maximal treadmill duration. Multiple logistic regression was used to estimate odds ratios of the metabolic syndrome as a function of the four PA categories, adjusted for age, ethnicity, study site, menopausal status, and use of hormone-replacement therapy. RESULTS: The adjusted odds ratio for the metabolic syndrome was 0.18 (95% confidence interval, 0.33 to 0.90) for women in the highest category of moderate-intensity PA compared with women in the lowest category (p = 0.01 for trend). Similar associations were observed for the metabolic syndrome with vigorous-intensity PA (p = 0.01 for trend) and maximal treadmill duration (p = 0.0004 for trend). DISCUSSION: Higher levels of moderate and vigorous-intensity PA and greater maximal treadmill duration were inversely associated with the metabolic syndrome among an ethnically diverse sample of women.

Adult↗

PubMed2002

Age and gender differences in objectively measured physical activity in youth.

PURPOSE: The purpose of this study was to evaluate age and gender differences in objectively measured physical activity (PA) in a population-based sample of students in grades 1-12. METHODS: Participants (185 male, 190 female) wore a CSA 7164 accelerometer for 7 consecutive days. To examine age-related trends, students were grouped as follows: grades 1-3 (N = 90), grades 4-6 (N = 91), grades 7-9 (N = 96), and grades 10-12 (N = 92). Bouts of PA and minutes spent in moderate-to-vigorous PA (MVPA) and vigorous PA (VPA) were examined. RESULTS: Daily MVPA and VPA exhibited a significant inverse relationship with grade level, with the largest differences occurring between grades 1-3 and 4-6. Boys were more active than girls; however, for overall PA, the magnitudes of the gender differences were modest. Participation in continuous 20-min bouts of PA was low to nonexistent. CONCLUSION: Our results support the notion that PA declines rapidly during childhood and adolescence and that accelerometers are feasible alternatives to self-report methods in moderately sized population-level surveillance studies.

Activities of Daily Living↗

PubMed2002

Differences in physical activity between black and white girls living in rural and urban areas.

This study examined the relationship of race and rural/urban setting to physical, behavioral, psychosocial, and environmental factors associated with physical activity. Subjects included 1,668 eighth-grade girls from 31 middle schools: 933 from urban settings, and 735 from rural settings. Forty-six percent of urban girls and 59% of rural girls were Black. One-way and two-way ANOVAs with school as a covariate were used to analyze the data. Results indicated that most differences were associated with race rather than setting. Black girls were less active than White girls, reporting significantly fewer 30-minute blocks of both vigorous and moderate-to-vigorous physical activity. Black girls also spent more time watching television, and had higher BMIs and greater prevalence of overweight than White girls. However, enjoyment of physical education and family involvement in physical activity were greater among Black girls than White girls. Rural White girls and urban Black girls had more favorable attitudes toward physical activity. Access to sports equipment, perceived safety of neighborhood, and physical activity self-efficacy were higher in White girls than Black girls.

Adolescent↗

PubMed2002

Examining social-cognitive determinants of intention and physical activity among black and white adolescent girls using structural equation modeling.

Structural equation modeling was used to evaluate components within the theories of reasoned action (TRA), planned behavior (TPB), and self-efficacy (SET) for understanding moderate and vigorous physical activity among 1,797 Black and White adolescent girls. Modest to strong support was provided for components of TPB and SET; weak support was provided for components of TRA. Perceived behavioral control was related to vigorous physical activity. Self-efficacy was related to moderate and vigorous physical activity, and it accounted for the effect of intention on physical activity. The observed relationships were similar between Black and White girls. Self-efficacy and perceived behavioral control are independent influences on physical activity among Black and White adolescent girls and warrant study as potential mediators in physical activity interventions.

Adolescent↗

PubMedDate not supplied

Evaluation of a community-based intervention to promote physical activity in youth: lessons from Active Winners.

PURPOSE: To test the effects of a community-based physical activity intervention designed to increase physical activity and to conduct an extensive process evaluation of the intervention. DESIGN: Quasi-experimental. SETTING: Two rural communities in South Carolina. One community received the intervention, and the other served as the comparison. SUBJECTS: Public school students who were in fifth grade at the start of the study (558 at baseline) were eligible to participate. A total of 436 students participated over the course of the study. INTERVENTION: The intervention included after-school and summer physical activity programs and home, school, and community components designed to increase physical activity in youth. The intervention took place over an 18-month period. MEASURES: Students reported after-school physical activity at three data collection points (prior to, during, and following the intervention) using the Previous Day Physical Activity Recall (PDPAR). They also completed a questionnaire designed to measure hypothesized psychosocial and environmental determinants of physical activity behavior. The process evaluation used meeting records, documentation of program activities, interviews, focus groups, and heart rate monitoring to evaluate the planning and implementation of the intervention. RESULTS: There were no significant differences in the physical activity variables and few significant differences in the psychosocial variables between the intervention and comparison groups. The process evaluation indicated that the after-school and summer physical activity component of the intervention was implemented as planned, but because of resource and time limitations, the home, school, and community components were not implemented as planned. CONCLUSIONS: The intervention did not have a significant effect on physical activity in the target population of children in the intervention community. This outcome is similar to that reported in other studies of community-based physical activity intervention.

Child↗

PubMedDate not supplied

Comparison of social variables for understanding physical activity in adolescent girls.

OBJECTIVE: To evaluate social support and theory of planned behavior (TPB) constructs in explaining physical activity in adolescent girls. METHODS: One thousand seven hundred ninety-seven 8th-grade girls completed a survey measuring social provisions, family support, TPB constructs, moderate-to-vigorous physical activity (MVPA), and team sport involvement (TSI). RESULTS: Structural equation modeling (SEM) indicated statistically significant direct effects from TPB constructs and social provisions to intention; social provisions, family support, and intention to MVPA; and social provisions and family support to TSI. CONCLUSIONS: Social variables play a greater role in explaining TSI than in explaining MVPA in this sample.

Adolescent↗