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Biomedical subjects

James R Morrow

Publications and source records attributed to James R Morrow.

9 recordsLinked to original sources

Weight stereotypes and behavioral intentions toward thin and fat peers among White and Hispanic adolescents.

PURPOSE: This study examined weight stereotypes among White and Hispanic youth. Specific objectives were to: (a) document stereotyped beliefs about fat vs. thin peers; (b) examine the extent to which stereotyped beliefs contribute to behavioral intentions toward fat vs. thin peers; and (c) explore potential differences in weight stereotypes and behavioral intentions in White and Hispanic youth. METHODS: Participants, 157 Hispanic and 117 White middle school students, completed a demographic and background survey, the Fat Stereotypes Questionnaire (FSQ), Adjective Checklist, and Shared Activities Questionnaire (SAQ). RESULTS: Participants endorsed weight-related stereotypes, which were predictive of their social, academic, and recreation behavioral intentions. Participants indicated greater willingness to engage in social (p < .001), academic (p < .05), and recreational (p < .001) activities with thin vs. fat peers. Few differences were found between White and Hispanic adolescents. CONCLUSIONS: The results of this study highlight the ubiquitous nature of stereotyped beliefs about fat youth. Fat youth are considered unhealthy, lazy, and socially inept by their peers. Such stereotypes influence a variety of behavioral intentions and may contribute to discriminatory behaviors and difficult peer relationships. Additional research focused on weight stereotypes and peer relationships is needed.

Adolescent↗

Assessing cardiorespiratory fitness without performing exercise testing.

BACKGROUND: Low cardiorespiratory fitness (CRF) is associated with increased risk of chronic diseases and mortality; however, CRF assessment is usually not performed in many healthcare settings. The purpose of this study is to extend previous work on a non-exercise test model to predict CRF from health indicators that are easily obtained. METHODS: Participants were men and women aged 20 to 70 years whose CRF level was quantified with a maximal or submaximal exercise test as part of the National Aeronautics and Space Administration/Johnson Space Center (NASA, n = 1863), Aerobics Center Longitudinal Study (ACLS, n = 46,190), or Allied Dunbar National Fitness Survey (ADNFS, n = 1706). Other variables included gender, age, body mass index, resting heart rate, and self-reported physical activity levels. RESULTS: All variables used in the multiple linear regression models were independently related to the CRF in each of the study cohorts. The multiple correlation coefficients obtained within NASA, ACLS, and ADNFS participants, respectively, were 0.81, 0.77, and 0.76. The standard error of estimate (SEE) was 1.45, 1.50, and 1.97 metabolic equivalents (METs) (1 MET = 3.5 ml O(2) uptake.kilograms of body mass(-1).minutes(-1)), respectively, for the NASA, ACLS, and ADNFS regression models. All regression models demonstrated a high level of cross-validity (0.72 < R < 0.80). The highest cross-validation coefficients were seen when the NASA regression model was applied to the ACLS and ADNFS cohorts (R = 0.76 and R = 0.75, respectively). CONCLUSIONS: This study suggests that CRF may be accurately estimated in adults from a non-exercise test model including gender, age, body mass index, resting heart rate, and self-reported physical activity.

Adult↗

Construct validity of self-reported historical physical activity.

The purpose of this study was to determine the construct-related validity of self-reported historical walking, running, and jogging (WRJ) activity on the basis of data from the Aerobics Center Longitudinal Study (Dallas, Texas). A total of 4,100 men and 963 women underwent at least one medical examination between 1976 and 1985 and completed a follow-up questionnaire in 1986. Levels of glucose, cholesterol, and triglycerides, resting systolic blood pressure, body mass index (weight (kg)/height (m)(2)), and cardiorespiratory fitness were measured at the time of the medical examination. The follow-up questionnaire assessed WRJ and other strenuous activities for each year from 1976 through 1985. Data analysis included Spearman and partial correlations, analysis of variance, analysis of covariance, and t tests. Results indicated significant correlations between recalled WRJ and treadmill times for each year throughout the 10-year period (r = 0.40-0.61). Participants were classified as historically either sufficiently physically active to receive a health benefit or insufficiently active for a health benefit. Engaging in sufficient levels of historical WRJ was associated with higher treadmill times and lower body mass indices for men and women and lower triglyceride levels for men. Self-reported historical WRJ can be assessed with reasonable validity in comparison with measured treadmill performance, with no decay in accuracy of reporting for up to 10 years in the past.

Adolescent↗

American adults' knowledge of exercise recommendations.

Physical inactivity is a major risk factor for cardiovascular disease, stroke, hypertension, diabetes, obesity, osteoporosis, and some cancers. Approximately 950,000 Americans die annually from cardiovascular diseases. The purpose of this study was to determine whether American adults know which traditional and lifestyle physical activities affect health and how they should be physically active to achieve a health benefit. Secondary purposes were to determine whether this knowledge is a function of gender, ethnicity, education, or age and if those who are sufficiently active for a health benefit possess different knowledge levels than those not sufficiently active for a health benefit. Items based on the Centers for Disease Control and Prevention/American College of Sports Medicine principles included knowledge of exercise guidelines and traditional and lifestyle physical activities. This information was obtained from 20 questions that were part of a national random telephone survey of 2,002 American households in the 48 contiguous states and the District of Columbia. Respondents were most aware of traditional physical activities (M = 94%) that provide a health benefit and less aware of specific exercise guidelines (M = 68%) and lifestyle physical activities (M = 71%) that can result in a health benefit. Knowledge was not related to physical activity behavior sufficient for a health benefit and only slightly related to ethnicity, education, and age. These data suggest that physical activity knowledge alone is not sufficient to elicit a behavior; however, it provides educators with an understanding of the public's physical activity knowledge that could be helpful in developing health promotion and physical activity interventions.

Adolescent↗

Longitudinal changes in cardiorespiratory fitness: measurement error or true change?

PURPOSE: This study examined the thesis that the reported Aerobics Center Longitudinal Study (ACLS) mortality reductions associated with improved cardiorespiratory fitness were because of measurement error of serial treadmill tests. We tested the research hypothesis that longitudinal changes in cardiorespiratory fitness of the ACLS cohort were a multivariate function of changes in self-report physical activity (SR-PA), resting heart rate, and body mass index (BMI). METHODS: We used the results of three serial maximal treadmill tests (T1, T2, and T3) to evaluate the serial changes in cardiorespiratory fitness of 4675 men. The mean duration between the three serial tests examined was: T2 - T1, 1.9 yr; T3 - T2, 6.1 yr; and T3 - T1, 8.0 yr. Maximum and resting heart rate, BMI, SR-PA, and maximum Balke treadmill duration were measured on each occasion. RESULTS: General linear models analysis showed that with change in maximum heart rate statistically controlled change in treadmill time performance was a function of independent changes in SR-PA, BMI, and R-HR. These variables accounted for significant (P < 0.001) proportions (7%, 9%, and 12%) of the change in treadmill time variance. Those men who increased their SR-PA and lowered their BMI and resting heart rate gained the most fitness between serial tests. CONCLUSIONS: These results support the research hypothesis tested. Variations in serial ACLS treadmill tests are not just due to measurement error alone, but also to systematic variation linked with changes in lifestyle.

Adult↗

Reliability of accelerometry-based activity monitors: a generalizability study.

INTRODUCTION: Numerous studies have examined the validity of accelerometry-based activity monitors but few studies have systematically studied the reliability of different accelerometer units for assessing a standardized bout of physical activity. Improving understanding of error in these devices is an important research objective because they are increasingly being used in large surveillance studies and intervention trials that require the use of multiple units over time. METHODS: Four samples of college-aged participants were recruited to collect reliability data on four different accelerometer types (CSA/MTI, Biotrainer Pro, Tritrac-R3D, and Actical). The participants completed three trials of treadmill walking (3 mph) while wearing multiple units of a specific monitor type. For each trial, the participant completed a series of 5-min bouts of walking (one for each monitoring unit) with 1-min of standing rest between each bout. Generalizability (G) theory was used to quantify variance components associated with individual monitor units, trials, and subjects as well as interactions between these terms. RESULTS: The overall G coefficients range from 0.43 to 0.64 for the four monitor types. Corresponding intraclass correlation coefficients (ICC) ranged from 0.62 to 0.80. The CSA/MTI was found to have the least variability across monitor units and trials and the highest overall reliability. The Actical was found to have the poorest reliability. CONCLUSION: The CSA/MTI appeared to have acceptable reliability for most research applications (G values above 0.60 and ICC values above 0.80), but values with the other devices indicate some possible concerns with reliability. Additional work is needed to better understand factors contributing to variability in accelerometry data and to determine appropriate calibration protocols to improve reliability of these measures for different research applications.

Adult↗

The relationship of body mass index, medical costs, and job absenteeism.

OBJECTIVES: To assess the relationship between body mass index, as categorized by the recently released guidelines of the NHLBI, and health care costs and absenteeism in a sample of municipal workers. METHODS: A cross-sectional study was employed that compared the obesity-related health care costs and absences of normal and overweight/obese city workers. RESULTS: While accounting for age, gender, race, smoking behavior, and educational attainment, BMI predicted both average annual health-care costs and work absence hours. CONCLUSIONS: The NHLBI guidelines for overweight and obesity effectively predicted absences and health care costs.

Absenteeism↗