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Biomedical subjects

Bess H Marcus

Publications and source records attributed to Bess H Marcus.

24 records · Page 2Linked to original sources
PubMed2002

User attitudes toward a physical activity promotion website.

BACKGROUND: The goal of the present study was to examine participants' perceptions of a theory-driven, physical activity promotion website. METHODS: Participants in the present study were individuals in the website condition of a randomized trial designed to test the efficacy of the website. At 1 month, participants were surveyed regarding their self-report of barriers, frequency of use, and helpfulness of the website. RESULTS: Overall, 30 worksite participants were randomized to the website condition and 24 (80%) completed the survey at 1 month. The main barrier to using the website was a "lack of time" (63%). No participants endorsed trouble using the website, a lack of interest in using the internet, or a lack of interest in changing their activity level as barriers to using the website. Furthermore, most sections of the website were found to be "helpful." Patterns of use and perceived utility differed by readiness to become active. For example, more respondents in the "preparation" stage at baseline reported using the overall website, in addition to the "becoming active" and "physical activity and health" sections, than those in the "contemplation" stage at baseline. Perceived utility and frequency of use of specific sections were often divergent, where some sections were rated more helpful and used less frequently (the "Overcoming Barriers" section, for example), while the reverse was true for other sections (the "Walking Fitness Test" section, for example). CONCLUSION: In conclusion, the website was well accepted and few barriers were noted. Areas of the website that were used less frequently or found to be less helpful will become areas of focus for future iterations of the site.

Adolescent↗
PubMed2002

Effects of a computer-based, telephone-counseling system on physical activity.

BACKGROUND: There is increasing interest in developing interventions to promote physical activity (PA) that do not involve face-to-face contact with health professionals. We developed a fully automated PA counseling system (telephone-linked communication, TLC-PA) that was delivered via telephone. DESIGN: A randomized, controlled trial with 298 adult, sedentary members (mean age, 45.9 years; 72% women; 45% white; and 45% African American) of a multi-site medical practice. The comparison group (TLC-Eat) received an automated intervention promoting healthy eating, which was also delivered via telephone. INTERVENTION: The TLC-PA promoted moderate-intensity PA (MI-PA) based on the transtheoretical model of behavior change and social cognitive theory. The system was available to participants for 6 months. MAIN OUTCOMES: Energy expenditure in MI-PA, proportion of participants who met recommendations for MI-PA, and motivational readiness for PA. MEASURES: Self-reports of PA behavior and motivational readiness at baseline, 3 months, and 6 months. RESULTS: At 3 months, intention-to-treat analyses showed that the TLC-PA group was more likely to meet recommendations for MI- or vigorous-intensity PA (VI-PA) compared to the TLC-Eat group (TLC-PA=26% vs TLC-Eat=19.6%, p=0.04). Among study completers, TLC-PA subjects reported significantly higher daily kilocalorie energy expenditure in MI-PA (2.3 kcal/kg/d vs 2.0 kcal/kg/d, p=0.02); a larger proportion met recommendations for MI- or VI-PA (31.2% vs 21.3%, p=0.02) and were in more advanced stages of motivational readiness than TLC-Eat subjects (TLC-PA=52.5% vs TLC-Eat=42.2%, p=0.04). Results were not maintained at 6 months. The proportion of TLC-PA users decreased significantly over the intervention period. CONCLUSIONS: A fully automated counseling system had positive short-term effects on PA among sedentary adults. Lack of maintenance of effects may be due to a decrease in the number of participants who continued to use the system.

Chi-Square Distribution↗
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

Impact of weight-cycling history on bone density in obese women.

OBJECTIVE: The purpose of this study was to examine the effect of weight cycling (as defined by the frequency and magnitude of intentional weight loss) on bone mineral density and bone mineral content in obese sedentary women. RESEARCH METHODS AND PROCEDURES: Bone mineral content and density measured by DXA, submaximal physical fitness assessment, nutrient intake, oral contraceptive use, and weight-cycling history were assessed in 195 healthy, overweight sedentary women (age, 21 to 45 years; body mass index, 27 to 40 kg/m(2)) before beginning a behavioral weight-loss intervention. RESULTS: After controlling for body weight, multivitamin use, oral contraceptive/estrogen use, and calcium and magnesium intake, women who had a history of weight cycling did not have significantly lower total-body bone mineral content or density or total femur bone mineral density. In addition, 99% of subjects were above or within one SD of age and gender normative data for total femur bone mineral density. DISCUSSION: It does not seem that a history of weight cycling has an adverse affect on total femur and total-body bone mineral density in overweight sedentary premenopausal women.

Absorptiometry, Photon↗
PubMedDate not supplied

Reaching out to promote physical activity in Australia: a statewide randomized controlled trial of a stage-targeted intervention.

PURPOSE: This study examined the broader use of a print-media intervention, which was previously shown to be effective at promoting physical activity to participants recruited from a regional Australian community, as a strategy suitable for a more diverse statewide population sample. METHODS: Participants were randomly selected adults who responded to a telephone interview conducted by the New South Wales Health Department and consented to participate in a randomized controlled trial. Consenters were allocated to either intervention (n = 361) or control (n = 358) conditions. The intervention, a personalized letter plus stage-targeted booklets, was sent 1 week postbaseline. Data were collected via telephone interview at baseline and 2 and 8 months and were analyzed using repeated measures analysis of variance (ANOVA) and chi2 statistics. RESULTS: The groups were similar at baseline (mean age 43 +/- 3 years; 64% women). Process evaluation showed high intervention recall (76% at 2 months) and high follow-up response rates (> 85% at 8 months) were achieved. Nonsignificant increases in physical activity were observed (F1,719 = 2.18, p = .14). DISCUSSION: A single mailing of stage-targeted print materials was not effective in promoting increases in physical activity among participants selected from the statewide population. Future research could examine how the effectiveness of print media might be enhanced, possibly by using supplementary media, community-based prompts, or other incentives.

Adult↗