Prescribing physical activity: applying the ACSM protocols for exercise type, intensity, and duration across 3 training frequencies.

When physicians advise patients to attain more physical activity, they usually recommend a walking program. However, in a similar way to no exercise, those embarking on a walking program will typically lose 4 to 6 lb of lean weight and reduce their resting metabolic rate 2% to 3% every decade. These effects may be mitigated by the inclusion of resistance exercise. The American College of Sports Medicine (ACSM) minimum exercise guidelines recommend 20 minutes of aerobic activity 3 days per week, and 1 set (8-12 repetitions) of 8 to 10 resistance exercises to train the major muscle groups 2 days per week. However, large-scale testing of these recommendations in a field setting has been minimal. Men and women between 21 and 80 years (N = 1725) [corrected] participated in a 10-week combined strength and aerobic activity program based on the ACSM protocols for exercise intensity and duration across 3 training frequencies (1, 2, or 3 sessions/week). Across all training frequencies, mean changes included a reduction in body fat of 1.97%, a decrease in fat weight of 1.7 kg, an increase in lean weight of 1.35 kg, a reduction in systolic blood pressure of 3.83 mm Hg, and a reduction in diastolic blood pressure of 1.73 mm Hg. More frequent weekly training sessions were associated with greater improvements in body fat percent, fat weight, and lean weight. Participants responded favorably to the ACSM exercise program with a 91% completion rate and a 95% satisfaction rating. This article presents recommendations for prescribing safe, effective, and time-efficient exercise programs.

Small changes in nutrition and physical activity promote weight loss and maintenance: 3-month evidence from the ASPIRE randomized trial.

BACKGROUND: Current obesity interventions use intensive behavior changes to achieve large initial weight loss. However, weight regain after treatment is common, and drop out rates are relatively high. Smaller behavioral changes could produce initial weight loss and be easier to sustain after active treatment. PURPOSE: We examined the efficacy of an intervention that targeted small but cumulative participant-chosen changes in diet and physical activity (ASPIRE) and compared this treatment to standard didactic and wait-list control groups. The primary outcome measures were body weight, waist circumference, and intra-abdominal fat. METHODS: Fifty-nine overweight or obese sedentary adults were randomized to one of three groups: (1) the ASPIRE group (n = 20), (2) a standard educationally-based treatment group (n = 20), or (3) a wait list control group (n = 19) for 4 months. Active treatment groups received identical resistance and aerobic training programs. RESULTS: Intention-to-treat analyses showed that participants in the ASPIRE group lost significantly more weight than the standard and control groups (-4.4 vs. -1.1 and +0.1 kg, respectively), and the greater initial weight loss in the ASPIRE group was sustained 3 months after active treatment (4.1 kg). An alternative analytic strategy (0.3 kg/month weight gain for those lost to follow-up) showed continued weight loss (-0.2 kg after active treatment; -4.6 kg from baseline) at follow-up in the ASPIRE group. Similar patterns were observed for the other adiposity measures. CONCLUSION: More modest behavioral changes are capable of promoting weight loss, decreasing adiposity markers and sustaining these changes over 3 months. Longer-term studies comparing this approach with traditional behavioral weight loss treatments are warranted.

Social-cognitive determinants of physical activity: the influence of social support, self-efficacy, outcome expectations, and self-regulation among participants in a church-based health promotion study.

A social-cognitive model of physical activity was tested, using structural equation analysis of data from 999 adults (21% African American; 66% female; 38% inactive) recruited from 14 southwestern Virginia churches participating in the baseline phase of a health promotion study. Within the model, age, race, social support, self-efficacy, and self-regulation contributed to participants' physical activity levels, but outcome expectations did not. Of the social-cognitive variables, self-regulation exerted the strongest effect on physical activity. Independent of self-regulation, self-efficacy had little effect. Social support influenced physical activity as a direct precursor to self-efficacy and self-regulation. The model provided a good fit to the data and explained 46% of the variance in physical activity among the diverse group of adults.

Outcomes of a randomized, controlled community-level HIV prevention intervention for adolescents in low-income housing developments.

OBJECTIVES: Youth are increasingly at risk for contracting HIV infection, and community-level interventions are needed to reduce behavioral risk. DESIGN: A randomized, controlled, multi-site community-level intervention trial was undertaken with adolescents living in 15 low-income housing developments in five US cities. METHODS: Baseline (n = 1172), short-term follow-up (n = 865), and long-term follow-up (n = 763) risk assessments were conducted among adolescents, ages 12-17, in all 15 housing developments. The developments were randomly assigned in equal numbers to each of three conditions: experimental community-level intervention (five developments); "state-of-the-science" skills training workshops (five developments); and, education-only delayed control intervention (five developments). RESULTS: At long-term follow-up, adolescents living in the housing developments receiving the community-level intervention were more likely to delay onset of first intercourse (85%) than those in the control developments (76%), while those in the workshop developments (78%) did not differ from control condition adolescents. Adolescents in both the community-level intervention (77%) and workshop (76%) developments were more likely to use a condom at last intercourse than those in control (62%) developments. CONCLUSIONS: Community-level interventions that include skills training and engage adolescents in neighborhood-based HIV prevention activities can produce and maintain reductions in sexual risk behavior, including delaying sexual debut and increasing condom use.

Emotional distress in nonmetropolitan persons living with HIV disease enrolled in a telephone-delivered, coping improvement group intervention.

The study delineated depressive symptoms and modeled emotional distress in persons living with HIV disease in nonmetropolitan areas of 13 U.S. states. Participants (N=329) were enrolled in a randomized clinical trial of a telephone-delivered, coping improvement group intervention, and 60% reported moderate or severe levels of depressive symptomatology on the Beck Depression Inventory. Structural equation modeling indicated that participants who experienced more severe HIV symptomatology, received less social support, and engaged in more avoidant coping also experienced more emotional distress (a latent construct comprising depressive symptoms and emotional well-being). Greater HIV-related stigma and rejection by family led to more emotional distress, with social support and avoidant coping mediating almost entirely the effects of the former 2 variables. The model accounted for 72% of the variance in emotional distress in nonmetropolitan persons living with HIV disease.

HIV risk behavior among ethnically diverse adolescents living in low-income housing developments.

PURPOSE: To describe patterns and predictors of HIV risk behaviors among ethnically diverse, low-income adolescents. METHODS: Computer-assisted surveys were administered to 1172 adolescents between the ages of 12 and 17 years living in 15 low-income housing developments in three urban areas in the United States to characterize and identify predictors of HIV risk behavior. Data were analyzed using multinomial logistic regression to identify variables predictive of "no risk," "lower risk," and "higher risk" group classification. RESULTS: Most adolescents were not yet sexually active; nonetheless, a subset of youth reported high rates of HIV risk-related behaviors. HIV risk was highest among adolescents who were older, had weaker intentions to reduce risk, stronger beliefs that their sexual partners did not favor risk-reduction, lower risk-reduction behavioral skills, higher risk-reduction outcome expectation, and higher rates of substance use. CONCLUSIONS: HIV prevention efforts are needed that are tailored to ethnically diverse communities of adolescents, including those in early adolescence and those at highest risk.

DASH to wellness: emphasizing self-regulation through e-health in adults with prehypertension.

OBJECTIVE: High prevalence rates of prehypertension require nonpharmaceutical lifestyle interventions. The objective of this study was to assess the feasibility and initial efficacy of a primarily electronically delivered intervention for prehypertension. METHODS: Twenty-three adults with prehypertension (M age of 54.3; systolic blood pressure [BP], 126.3 mmHg; weight, 87.8 kg; body mass index, 31.5; 6514 steps/day) were randomized to DASH 2 wellness only standard of care or to DASH 2 wellness plus. Both groups received instruction on the DASH eating plan, instructions to increase steps per day and use of a weight scale and pedometer, and information about social-cognitive theory-based self-regulation strategies. D2W plus also involved home blood pressure monitoring and monitoring steps per day, nutrition, and body weight. Through weekly newsletters, participants engaged in electronic reporting and goal setting and received feedback on progress. RESULTS: D2W plus showed a larger increase in daily steps (M = 2,900) than D2W only (M = 636); a larger decrease in systolic BP (mmHg), M = 15.1 versus M = 4.6, and a larger decrease in weight (in kg), M = 4.8 versus M = 1.5. CONCLUSIONS: Concentrating efforts not only toward adoption and initiation of innovative risk-reduction strategies but also toward the provision for long-term maintenance of a healthy lifestyle once initial changes have been accomplished is paramount. The D2W plus program could be adapted for such use in health care and other settings for treating prehypertension.

Guide to Health: A Randomized Controlled Trial of the Effects of a Completely WEB-Based Intervention on Physical Activity, Fruit and Vegetable Consumption, and Body Weight.

BACKGROUND: Theory-based, efficacious, long-term, completely Internet-based interventions are needed to induce favorable shifts in health behaviors and prevent weight gain. PURPOSE: To assess nutrition, physical activity, and, secondarily, body weight outcomes in the tailored, social cognitive theory Guide to Health (WB-GTH) program with all recruitment, assessment, and intervention performed on the Internet. METHODS: The focus of the efficacy study was engaged participants who completed 3 or more program modules plus baseline, 6-months post and, 16-months follow-up assessments (n = 247). To be eligible, participants needed to be between 18-63 years of age, with a BMI between 23-39, sedentary to low-active but otherwise healthy. Participant had a mean age of 45.5 years (10.3), 86.2% were female, with 8.5% from minority groups, with a mean 17.5 (3.0) years of education, and had a median annual household income of about $85k. Nevertheless, about 83% were overweight or obese and about 75% were sedentary (i.e., <5000 steps/day) or had low levels of activity (i.e., 5,000 - 7499 steps/day). Participants were randomized to the WB-GTH-Basic intervention or WB-GTH-Enhanced intervention. Content, overall target behaviors, program goals and strategies were the same in the two interventions with the difference that Basic included a generic feedback and planning approach and Enhanced included a highly tailored planning and feedback approach. Participants reported at assessments pedometer step counts to assess physical activity, bodyweight from a scale provided, and fruit and vegetable (F&V) servings were assessed from food frequency questionnaires completed online. RESULTS: Participants in both Basic and Enhanced at follow-up increased physical activity by about 1400 steps/day, lost about 3% of bodyweight, and increased F&V by about 1.5 serving/day. There was evidence that the least physically active, those who were obese, and those with poorest nutrition made greater long-term improvements. CONCLUSIONS: Given similar outcomes for Basic and Enhanced, a relatively simple entirely Internet-based program can help people improve health behaviors and prevent weight gain.

Social cognitive mediators of change in a group randomized nutrition and physical activity intervention: social support, self-efficacy, outcome expectations and self-regulation in the guide-to-health trial.

In an evaluation of the theoretical foundations of behavior change, the current study examined whether social cognitive (SCT) variables mediated treatment effects on physical activity and nutrition in the recently reported Guide-to-Health trial (GTH). Adults (N = 661) were assessed at baseline, seven months and 16 months to examine whether treatment-related changes in SCT variables at seven months mediated change in nutrition and physical activity at 16 months. GTH treatment effects were mediated by self-efficacy, self-regulation and social support; self-regulation mediated self-efficacy. Social-cognitive variables explained only part of the treatment effects suggesting future investigations evaluate the environmental-selection and affective processes of behavior change.

Web-based nutrition education intervention improves self-efficacy and self-regulation related to increased dairy intake in college students.

Dairy consumption declines substantially during young adulthood. Interventions that incorporate theory-based nutrition education can provide insight into factors associated with dietary choices. The aim of this experimental study was to improve outcome expectations, self-efficacy, self-regulation, and behavior related to dairy intake in college students using social cognitive theory. Students (n=294) enrolled in a personal health class were randomized to intervention (n=148) or comparison group (n=146). The 5-week intervention (March 2006 to April 2006) was conducted using an online course system; components included e-mail messages, posted information, and behavior checklists with tailored feedback. Multivariate analysis of covariance with age and sex as covariates (P<0.05) was conducted to measure change related to dairy intake and social cognitive theory variables. Ninety-two percent of participants (n=135 intervention, n=136 control) completed the study. Dairy intake from food records did not differ between groups at baseline; baseline intake for all participants (mean ± standard error) was 0.45 ± 0.05 servings/day for low-fat dairy products and 1.44 ± 0.06 servings/day for total dairy products. Participants in the intervention group made greater increases in use of self-regulatory strategies (P=0.038) and self-efficacy for consuming three servings/day of dairy products (P=0.049), but not in outcome expectations or consumption of dairy products. A Web-based intervention designed to change dairy intake in college students was effective in modifying some social cognitive theory constructs; strategies that positively impact outcome expectations and social support through online interventions require further development.

Low-fat dairy intake and body weight and composition changes in college students.

Dairy calcium may help prevent excess weight gain and obesity when consumed in adequate amounts (three or more servings per day) and combined with energy balance. This prospective cohort study was conducted to evaluate dairy intake and examine the association between low-fat dairy intake and body weight and composition changes in college students. Seventy-six college students (65 women and 11 men; mean age+/-standard error [SE]=19.2+/-0.2 years) completed 7-day food records, body height (cm), weight (kg), and waist circumference (cm) measurements twice (September 2004 and April 2005). Percentage of truncal fat and percentage of total body fat were measured by dual-energy x-ray absorptiometry. One-way multivariate analysis of covariance was conducted. Overall (mean+/-SE) total dairy (1.4+/-0.1 servings/day), low-fat dairy (0.5+/-0.1 servings/day), and calcium (815+/-41 mg/day) intakes were low. Subjects who consumed a higher amount of low-fat dairy products (mean+/-SE=0.8+/-0.1 servings/day) had better diet quality, gained less body weight, and had reductions in waist circumference, percentage truncal fat, and percentage total body fat compared to those with lower intake (mean+/-SE=0.1+/-0.0 servings/day). Low-fat dairy intake may be associated with better diet quality and weight management in college students. Nutrition interventions in young adults should promote low-fat dairy intake as part of an overall healthful lifestyle.

Self-regulation, self-efficacy, outcome expectations, and social support: social cognitive theory and nutrition behavior.

BACKGROUND: Understanding the need for and accessibility to healthier foods have not improved the overall diets of the U.S. population. Social cognitive theory (SCT) may explain how other variables, such as self-regulation and self-efficacy, may be key to integrating healthier nutrition into U.S. lifestyles. PURPOSE: To determine how SCT accounts for the nutritional content of food purchases and consumption among adults in a health promotion study. METHODS: Participants were 712 churchgoers (18% African American, 66% female, 79% overweight or obese) from 14 churches in southwestern Virginia participating in the baseline phase of a larger health promotion study. Data were collected on the nutrition related social support, self-efficacy, outcome expectations, and self-regulation components of SCT, as well as on the fat, fiber, fruit, and vegetable content of food-shopping receipts and food frequency questionnaires. These data were used to test the fit of models ordered as prescribed by SCT and subjected to structural equation analysis. RESULTS: SCT provided a good fit to the data explaining 35%, 52%, and 59% of observed variance in percent calories from fat, fiber g/1000 kcals and fruit and vegetable servings/1000 kcals. Participants' age, gender, socioeconomic status, social support, self-efficacy, negative outcome expectations, and self-regulation made important contributions to their nutrition behavior -- a configuration of influences consistent with SCT. CONCLUSIONS: These results suggest a pivotal role for self-regulatory behavior in the healthier food choices of adults. Interventions effective at garnering family support, increasing nutrition related self-efficacy, and overcoming negative outcome expectations should be more successful at helping adults enact the self-regulatory behaviors essential to buying and eating healthier foods.

Guide to health: nutrition and physical activity outcomes of a group-randomized trial of an Internet-based intervention in churches.

BACKGROUND: Theory-based interventions accessible to large groups of people are needed to induce favorable shifts in health behaviors and body weight. PURPOSE: The aim was to assess nutrition; physical activity; and, secondarily, body weight in the tailored, social cognitive Guide to Health (GTH) Internet intervention delivered in churches. METHODS: Participants (N = 1,071; 33% male, 23% African American, 57% with body mass index > or = 25, 60% sedentary, Mdn age = 53 years) within 14 Baptist or United Methodist churches were randomized to the GTH intervention only (GTH-Only; 5 churches), with church-based supports (GTH-Plus; 5 churches), or to a waitlist (control; 4 churches). Verified pedometer step counts, measured body weight, fat, fiber, and fruit and vegetable (F&V) servings from food frequency and supermarket receipts were collected at pretest, posttest (7 months after pretest), and follow-up (16 months after pretest). RESULTS: Participants in GTH-Only increased F&V at post (approximately 1.50 servings) compared to control (approximately 0.50 servings; p = .005) and at follow-up (approximately 1.20 vs. approximately 0.50 servings; p m = .038) and increased fiber at post (approximately 3.00 g) compared to control (approximately 1.5 g; p = .006) and follow-up (approximately 3.00 g vs. approximately 2.00 g; p = .040). GTH-Plus participants compared to control increased steps at post (approximately 1,500 steps/day vs. approximately 400 steps/day; p = .050) and follow-up (approximately 1,000 steps/day vs. approximately - 50 steps/day; p = .010), increased F&V at post (approximately 1.5 servings; p = .007) and follow-up (approximately 1.3 servings; p = .014), increased fiber at post (approximately 3.00A g; p = .013), and follow-up (approximately 3.00; p = .050) and decreased weight at post (approximately - 0.30 kg vs. approximately + 0.60 kg; p = .030). CONCLUSIONS: Compared to control, both GTH treatments improved nutrition at posttest, but church supports improved physical activity and nutrition at posttest and follow-up, suggesting environmental supports may improve Internet-based interventions.

Information-Motivation-Behavioral Skills (IMB) Model: testing direct and mediated treatment effects on condom use among women in low-income housing.

BACKGROUND: The Information-Motivation-Behavioral Skills (IMB) model of HIV preventive behavior (1-4) specifies that treatment effects on behavior occur largely as the result of treatment effects on behavioral skills, which follow from effects on information and motivation. PURPOSE: The objective was to determine whether the variables specified by the IMB model of HIV preventive behavior (1-4) accounted for the relation between an IMB-based treatment and resulting HIV preventive behavior (condom use). METHOD: Women (n = 557) living in 18 low-income housing developments in 5 geographically dispersed cities were recruited to participate in an HIV-prevention study. Women (within housing developments) were randomly assigned to receive an IMB-based, HIV risk-avoidance intervention or a comparison intervention. Baseline and posttreatment (16 months after baseline) data were collected on condom use information, motivation (social norms, attitudes, intentions, and perceived risk), enactment of behavioral skills (condom negotiation and procurement), and rates of condom use in the past 2 months. RESULTS: The IMB intervention led to a 12% to 16% increase in condom use rates over the course, whereas the comparison intervention led to 2% decrease. In addition, the IMB treatment led to greater increases in condom use information, in the intentions and social norms components of motivation and the condom procurement and condom conversations components of behavioral skills. The IMB model provided an acceptable fit to the data (root mean square error of approximation < .05) and accounted for 50% of the variance in posttreatment condom use among the sample. Treatment effects on condom use were almost entirely mediated by the IMB variables; specifically, motivation and enactment of behavioral skills mediated the intervention's impact on condom use. CONCLUSIONS: These results provide supporting evidence as to how theoretical variables operate to effect change within a theory-based intervention and provide evidence as to the applicability of a prevailing theory of HIV risk behavior among low-income minority women.

A review of the outcome expectancy construct in physical activity research.

BACKGROUND: Outcome expectancy is a central construct in social cognitive models of health behavior widely used as frameworks for physical activity research. PURPOSE: This article provides a review of the outcome expectancy construct and its application to research on physical activity. METHODS: Theoretical articles describing definitions and placement of outcome expectancy within social cognitive models, as well as empirical research on outcome expectancy and physical activity, were reviewed. RESULTS: Self-efficacy theory, the transtheoretical model, the theory of planned behavior, and protection motivation theory differ in their labeling and conceptualization of outcome expectancy but unanimously include expected outcomes of behavior. Preliminary empirical investigation of the role of outcome expectancy in understanding physical activity has yielded mixed results. Positive outcome expectancy appears to be more predictive of physical activity in older adults than in young to middle-aged adults, and personal barriers appear to be the most predictive subtype of negative outcome expectancy. In addition, a small number of studies indicate relations between outcome expectancy and other theoretical variables, including behavioral intention, stage of change, and self-efficacy. CONCLUSIONS: Further research on the role of outcome expectancy is necessary to design effective physical activity interventions. New directions in outcome expectancy research could involve (a) expanding the conceptualization of outcome expectancy to include expected outcomes of sedentary behavior and affective responses to physical activity, (b) further examination of potential moderators of the relation between outcome expectancy and physical activity (such as outcome value and outcome proximity), (c) distinguishing between the role of outcome expectancy in behavior onset versus behavior maintenance, (d) examining outcome expectancy as a mechanism of change in environmental intervention approaches, and (e) further analysis of interrelations between outcome expectancy and other social cognitive variables.

Long-term weight gain prevention: a theoretically based Internet approach.

BACKGROUND: A major focus of Healthy People 2010 is promoting weight management and physical activity because overweight, obesity, and a sedentary lifestyle are strongly associated with risk for heart disease and stroke, diabetes, cancers, and premature death. METHODS: Prevalence data and a focused review of weight management and physical activity studies point to the long-term weight gain prevention in normal weight (21-25 BMI), overweight (25-29 BMI), and even moderate obese (30-34 BMI) people as one alternative to prioritizing weight loss in health behavior interventions. This is because on a population basis annual weight gain is small (approximately 0.8 kg/year) and preventing weight gain appears to require only an energy shift of about 100 cal/day either through a modest increase in physical activity and/or consuming slightly less calories to maintain an energy balance. A more dynamic use of social cognitive theory (SCT) for developing programs to maintain health behavior changes is emerging with some evidence of long-term maintenance. The high use of the Internet provides a vehicle to reach different population segments with readily accessible, SCT-tailored long-term programs. Research studies using the Internet with tailored SCT interventions have shown changes in nutrition practices, physical activity, and weight loss for up to a year. CONCLUSIONS: One promising approach to weight gain prevention in population segments is the development and wide spread use of longer-term Internet programs using specific principles and procedures from SCT.

Social cognitive determinants of physical activity in young adults: a prospective structural equation analysis.

This study used a prospective design to test a model of the relation between social cognitive variables and physical activity in a sample of 277 university students. Social support, self-efficacy, outcome expectations, and self-regulation were measured at baseline and used to predict physical activity 8 weeks later. Results of structural equation modeling indicated a good fit of the social cognitive model to the data. Within the model, self-efficacy had the greatest total effect on physical activity, mediated largely by self-regulation, which directly predicted physical activity. Social support indirectly predicted physical activity through its effect on self-efficacy. Outcome expectations had a small total effect on physical activity, which did not reach significance. The social cognitive model explained 55% of the variance observed in physical activity.

Quality of life pilot intervention for breast cancer patients: use of social cognitive theory.

OBJECTIVE: The purpose of this article is to evaluate an 8-week pilot intervention based on Social Cognitive Theory to improve quality of life for women with breast cancer. METHODS: A total of 32 breast cancer patients were randomized to either the intervention or standard care. Outcome variables included quality of life, mood, self-efficacy, outcome expectations, and self-regulation. RESULTS: Effect sizes were calculated to examine the impact of the intervention, with moderate to large effect sizes found for several subscales of the outcome expectations variable: learning about cancer and treatment (d = 0.85), having a positive attitude (d = 0.54), talking about cancer (d = 1.02), engaging in relaxation (d = 0.62), and setting goals (d = 1.58). SIGNIFICANCE OF RESULTS: A nonparametric sign test was conducted, indicating that women in the intervention condition either improved more or showed less decline than the women in standard care, p = .034, two-tailed. Implications and suggestions for the content and delivery of future psychosocial interventions with cancer patients are reviewed.