Basics of qualitative research: Grounded theory procedures and techniques

The Theory of Planned Behaviour (TPB) has received considerable attention in the literature. The present study is a quantitative integration and review of that research. From a database of 185 independent studies published up to the end of 1997, the TPB accounted for 27% and 39% of the variance in behaviour and intention, respectively. The perceived behavioural control (PBC) construct accounted for significant amounts of variance in intention and behaviour, independent of theory of reasoned action variables. When behaviour measures were self-reports, the TPB accounted for 11% more of the variance in behaviour than when behaviour measures were objective or observed (R2s = .31 and .21, respectively). Attitude, subjective norm and PBC account for significantly more of the variance in individuals' desires than intentions or self-predictions, but intentions and self-predictions were better predictors of behaviour. The subjective norm construct is generally found to be a weak predictor of intentions. This is partly attributable to a combination of poor measurement and the need for expansion of the normative component. The discussion focuses on ways in which current TPB research can be taken forward in the light of the present review.

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Efficacy of the Theory of Planned Behaviour: a meta-analytic review.

The purpose of this Position Stand is to provide guidance to professionals who counsel and prescribe individualized exercise to apparently healthy adults of all ages. These recommendations also may apply to adults with certain chronic diseases or disabilities, when appropriately evaluated and advised by a health professional. This document supersedes the 1998 American College of Sports Medicine (ACSM) Position Stand, "The Recommended Quantity and Quality of Exercise for Developing and Maintaining Cardiorespiratory and Muscular Fitness, and Flexibility in Healthy Adults." The scientific evidence demonstrating the beneficial effects of exercise is indisputable, and the benefits of exercise far outweigh the risks in most adults. A program of regular exercise that includes cardiorespiratory, resistance, flexibility, and neuromotor exercise training beyond activities of daily living to improve and maintain physical fitness and health is essential for most adults. The ACSM recommends that most adults engage in moderate-intensity cardiorespiratory exercise training for ≥30 min·d on ≥5 d·wk for a total of ≥150 min·wk, vigorous-intensity cardiorespiratory exercise training for ≥20 min·d on ≥3 d·wk (≥75 min·wk), or a combination of moderate- and vigorous-intensity exercise to achieve a total energy expenditure of ≥500-1000 MET·min·wk. On 2-3 d·wk, adults should also perform resistance exercises for each of the major muscle groups, and neuromotor exercise involving balance, agility, and coordination. Crucial to maintaining joint range of movement, completing a series of flexibility exercises for each the major muscle-tendon groups (a total of 60 s per exercise) on ≥2 d·wk is recommended. The exercise program should be modified according to an individual's habitual physical activity, physical function, health status, exercise responses, and stated goals. Adults who are unable or unwilling to meet the exercise targets outlined here still can benefit from engaging in amounts of exercise less than recommended. In addition to exercising regularly, there are health benefits in concurrently reducing total time engaged in sedentary pursuits and also by interspersing frequent, short bouts of standing and physical activity between periods of sedentary activity, even in physically active adults. Behaviorally based exercise interventions, the use of behavior change strategies, supervision by an experienced fitness instructor, and exercise that is pleasant and enjoyable can improve adoption and adherence to prescribed exercise programs. Educating adults about and screening for signs and symptoms of CHD and gradual progression of exercise intensity and volume may reduce the risks of exercise. Consultations with a medical professional and diagnostic exercise testing for CHD are useful when clinically indicated but are not recommended for universal screening to enhance the safety of exercise.

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Quantity and Quality of Exercise for Developing and Maintaining Cardiorespiratory, Musculoskeletal, and Neuromotor Fitness in Apparently Healthy Adults: Guidance for Prescribing Exercise

The primary purpose of this narrative review was to evaluate the current literature and to provide further insight into the role physical inactivity plays in the development of chronic disease and premature death. We confirm that there is irrefutable evidence of the effectiveness of regular physical activity in the primary and secondary prevention of several chronic diseases (e.g., cardiovascular disease, diabetes, cancer, hypertension, obesity, depression and osteoporosis) and premature death. We also reveal that the current Health Canada physical activity guidelines are sufficient to elicit health benefits, especially in previously sedentary people. There appears to be a linear relation between physical activity and health status, such that a further increase in physical activity and fitness will lead to additional improvements in health status.

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Health benefits of physical activity: the evidence

Conceptual and methodological ambiguities surrounding the concept of perceived behavioral control are clarified. It is shown that perceived control over performance of a behavior, though comprised of separable components that reflect beliefs about self-efficacy and about controllability, can nevertheless be considered a unitary latent variable in a hierarchical factor model. It is further argued that there is no necessary correspondence between self-efficacy and internal control factors, or between controllability and external control factors. Self-efficacy and controllability can reflect internal as well as external factors and the extent to which they reflect one or the other is an empirical question. Finally, a case is made that measures of perceived behavioral control need to incorporate self-efficacy as well as controllability items that are carefully selected to ensure high internal consistency.

Summary and Conclusions
Perceived control over performance of a behavior can account for consider- able variance in intentions and actions. However, ambiguities surrounding the concept of perceived behavioral control have tended to create uncertainties and to impede progress. The present article attempted to clarify conceptual ambiguities and resolve issues related to the operationalization of perceived behavioral control. Recent research has demonstrated that the overarching concept of perceived behavioral control, as commonly assessed, is comprised of two components: self-efficacy (dealing largely with the ease or difficulty of performing a behavior) and controllability (the extent to which performance is up to the actor). Contrary to a widely accepted view, it was argued that self-efficacy expectations do not necessarily correspond to beliefs about internal control factors, and that controllability expectations have no necessary basis in the perceived operation of external factors. Instead, it was suggested that self-efficacy and controllability may both reflect beliefs about the presence of internal as well as external factors. Rather than making a priori assumptions about the internal or external locus of self-efficacy and controllability, this issue is best treated as an empirical question.

Also of theoretical significance, the present article tried to dispel the notion that self-efficacy and controllability are incompatible with, or independent of, each other. Although factor analyses of perceived behavioral control items provide clear and consistent evidence for the distinction, there is sufficient commonality between self-efficacy and controllability to suggest a two-level hierarchical model. In this model, perceived behavioral control is the overarching, superordinate construct that is comprised of two lower-level components: self-efficacy and controllability. This view of the control component in the theory of planned behavior implies that measures of perceived behavioral control should contain items that assess self-efficacy as well as controllability. Depending on the purpose of the investigation, a decision can be made to aggregate over all items, treating perceived behavioral control as a unitary factor, or to distinguish between self-efficacy and controllability by entering separate indices into the prediction equation.

Perceived Behavioral Control, Self-Efficacy, Locus of Control, and the Theory of Planned Behavior

Effects of a Health-Based versus Appearance-Based Persuasive Message on Attitudes Towards Exercise

Insulin, insulin-like growth factors (IGFs) I and II, and IGF binding proteins (IGFBPs) 1 and 3 have been implicated in breast cancer outcomes. We conducted a randomized controlled trial to determine the physiological effects of exercise training on changes in these biological markers in postmenopausal breast cancer survivors. Fifty-three postmenopausal breast cancer survivors were randomly assigned to an exercise ( n = 25) or control group ( n = 28). The exercise group trained on cycle ergometers three times per week for 15 weeks. The control group did not train. End points included changes in fasting insulin, glucose, insulin resistance, IGF-I, IGF-II, IGFBP-1, IGFBP-3, and IGF-I:IGFBP-3 molar ratio between baseline and week 15. All of the statistical tests were two-sided (α = 0.05). Fifty-two participants completed the trial. The exercise group completed 44.3 of 45 (98.4%) prescribed exercise sessions. Baseline hormone concentrations did not differ between groups except that IGF-II was higher in the exercise group ( P = 0.011). No significant differences between groups were observed for changes in fasting insulin (+6.3 pmol/liter; P = 0.941), glucose (+0.09 mmol/liter; P = 0.824), insulin resistance (+0.4; P = 0.247), IGF-II (−40.7 ng/ml; P = 0.101), or IGFBP-1 (+1.4 ng/ml; P = 0.774). However, significant differences between groups were observed for changes in IGF-I (−7.4 ng/ml; P = 0.045), IGFBP-3 (+180.5 ng/ml; P = 0.021), and IGF-I:IGFBP-3 molar ratio (−0.006; P = 0.017). Exercise training had significant physiological effects on IGF-I, IGFBP-3, and IGF-I:IGFBP-3 molar ratio in postmenopausal breast cancer survivors. The clinical implications of these findings remain to be defined.

Effects of Exercise Training on Fasting Insulin, Insulin Resistance, Insulin-like Growth Factors, and Insulin-like Growth Factor Binding Proteins in Postmenopausal Breast Cancer Survivors

OBJECTIVES To examine the contributions of self-efficacy, outcome expectations, barriers, and demographic/health factors to physical activity behavior in primary care outpatients and to determine differences in these associations for African American versus Caucasian patients. DESIGN Cross-sectional, structured interview. PARTICIPANTS AND SETTING Adult internal medicine outpatients (n=393, response rate 88.5%) were enrolled. Most were female (70%) and Caucasian (62%) with a yearly household income <$20,000 (54%) and history of arthritis (57%). Mean age was 48.9+/-11.8 years and BMI was 30.9+/-8.16 kg/m2. MEASUREMENTS A 30-minute structured interview assessed self-reported leisure-time physical activity, self-efficacy, outcome expectations, perceived barriers, and demographic/ health covariates. RESULTS Based on path analysis, social cognitive constructs accounted for 28% of the variance in physical activity in African American patients and 25% in Caucasian patients. After controlling for selected covariates, path analysis showed a direct association between self-efficacy and physical activity for African American (beta=.45, P<.01) and Caucasian patients (beta=.34, P<.01). Although higher self-efficacy was associated with higher outcome expectations for both groups (beta=.25, P<.05, beta=.21, P<.05, respectively), no direct association was found for outcome expectations with activity. Self-efficacy demonstrated an indirect association with activity through perceived barriers for Caucasian patients only. CONCLUSIONS Self-efficacy and perceived barriers were the most important independent correlates of physical activity with potential racial differences warranting further study noted.

Racial differences in physical activity associations among primary care patients.

Introduction Active surveillance (AS) is the preferred primary treatment strategy for men with low-risk clinically localised prostate cancer (PCa); however, the majority of these men still receive radical treatment within 10 years due to disease progression and/or fear of cancer progression. Interventions designed to suppress tumour growth, mitigate fear of cancer progression and precondition men for impending radical treatments are an unmet clinical need. Exercise has been shown to delay the progression of prostate tumours in animal models, improve physical and functional health and manage psychological outcomes in cancer patients; however, these outcomes have not been demonstrated in PCa patients undergoing AS. Methods and analysis This phase II randomised controlled trial will randomise 66 men undergoing AS to either an exercise group or a usual care group. The exercise group will perform a 12-week, supervised, high-intensity interval training programme, consisting of 3 sessions/week for 28–40 min/session. The primary outcome will be cardiorespiratory fitness. Secondary outcomes will include immunosurveillance and cancer-related biomarkers, psychosocial outcomes including fear of cancer progression and quality of life and physical function. Exploratory outcomes will include clinical indicators of disease progression. The trial has 80% power to detect a significant between-group difference in VO2peak of 3.5 mL/kg/min with a two-tailed alpha level Ethics and dissemination The study has received full ethical approval from the Health Research Ethics Board of Alberta – Cancer Committee (Protocol Number: HREBA.CC-17–0248). The findings of the study will be disseminated through public and scientific channels. Trial registration number NCT03203460; Pre-results.

https://bmjopen.bmj.com/content/bmjopen/9/7/e026438.full.pdf

Exercise duRing Active Surveillance for prostatE cancer-the ERASE trial: a study protocol of a phase II randomised controlled trial

Given the magnitude of the diabetes epidemic among Canadian Aboriginals and the corresponding need to develop physical activity interventions, the aims of this study were to: 1) examine the meaning of physical activity; 2) assess physical activity behavior levels; and 3) examine the association of key Social Cognitive Theory (SCT) constructs with physical activity behavior. Thirty-four Aboriginals with diabetes completed a survey composed of questions regarding: 1) the perceived meaning of physical activity; 2) physical activity behavior; and 3) SCT constructs. An emerging theme revealed that some participants perceived physical activity leisure-time activities as appropriate across the lifespan, while the majority perceived leisure-time activities to be only for youth. Based on the reported energy expenditure estimates, 61.5% of participants were categorized as sedentary. However, when occupational and household activities were taken into account, 33.0% were categorized as sedentary. Bivariate correlations revealed that no SCT constructs were significantly associated with energy expenditure scores. Results suggest that specific SCT construct items may help understand physical activity behavior change. (Ethn Dis. 2005;15:256‐266)

Kerry S. Courneya

Papers

Effects of a Health-Based versus Appearance-Based Persuasive Message on Attitudes Towards Exercise

Effects of Exercise Training on Fasting Insulin, Insulin Resistance, Insulin-like Growth Factors, and Insulin-like Growth Factor Binding Proteins in Postmenopausal Breast Cancer Survivors

Racial differences in physical activity associations among primary care patients.

Exercise duRing Active Surveillance for prostatE cancer-the ERASE trial: a study protocol of a phase II randomised controlled trial

Physical activity of Aboriginals with type 2 diabetes: an exploratory study.