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Biomedical subjects

Allen W Jackson

Publications and source records attributed to Allen W Jackson.

5 recordsLinked to original sources
PubMed2006

Perceived submaximal force production in young adults.

The purpose of this investigation was to examine the force production patterns using perceived stimulus cues from 10% to 90% of maximal force. In Experiment 1, 54 men (age: 19-34 years) and 53 women (age: 18-37years) performed leg extensions on a dynamometer at a speed of 60 degrees/s. Participants produced actual forces perceived to be 10-90% of maximal force in 10% increments followed by a maximal force. A 2-min rest interval was maintained between each increment. Participants rested 5 min and repeated the protocol. Desired forces were calculated as the required percentage of the produced maximalforce. In Experiment 2, 40 men (age: 18-30years)followed the protocol ofExperiment 1, but the submaximal stimuli were randomly presented. In Experiment 1, test-retest results indicated consistency between the trials for actual and maximal force (r = .90). The correlations between actual and desired forces were moderately high (r > .76). Actual forces trended above desired forces at 10% of maximal, with median errors ranging 33-40% for men and 60-73% for women. From 30% to 90% of maximal forces, actual trended below desired forces, with median errors ranging from a low of 1.5% to a high of 37%. A power function analysis relating the change in actual force with desired force stimuli produced exponents of 0.68 (.95 CI = 0.62-0.74) for men and 0.5 7 (.95 CI = 0.52-0.62)for women. Findings were similar in Experiment 2, indicating that individuals tended to overshoot and then undershoot desired force production through perceptual force ranges of 10-90% of maximal forces and that force production grew more slowly than perceptual stimulus cues. The results of the present study, along with findings from past research, indicate that production of submaximal force using perceptual cues or stimuli display a great deal of specificity. This specificity is related to type of contraction, amount of muscle mass involved, and number and types of stimuli.

Adolescent↗
PubMed2004

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↗
PubMed2004

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↗
PubMedDate not supplied

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↗