Explaining adolescent exercise behavior change: a longitudinal application of the transtheoretical model

Adherence to physical activity recommendations and associations with self-efficacy among Norwegian adolescents: trends from 2017 to 2021

Background

The crucial role of physical activity (PA) in promoting well-being and overall health of adolescents is widely acknowledged. Previous global studies have consistently revealed low adherence to PA recommendations among adolescents, emphasizing potential links between PA engagement and self-efficacy in school-based populations. However, there is a need for further exploration of this relationship, in particularly gender differences and taking into account the potential influences of the COVID-19 pandemic. The objective of this study is to provide a comprehensive description of adherence to PA recommendations and its associations with self-efficacy in Norwegian school-based adolescents over the period from 2017 to 2021.

Methods

Cross-sectional data on physical activity (PA) levels and self-efficacy among 13-19-year-old Norwegian adolescents were collected from the Norwegian Ungdata Survey during the period 2017 to 2021. The survey, conducted in Norwegian lower- and upper-secondary schools, was administered electronically during school hours. All data collected is anonymous and has received approval from the Norwegian Agency for Shared Services in Education and Research (SIKT). Statistical analyses were performed using SPSS software.

Results

Girls consistently exhibited lower adherence to PA recommendations (17.6-19.8%) compared to boys (27.7-31.1%) each year from 2017 to 2021 (all p < 0.01). Similarly, girls reported lower self-efficacy (14.1 to 14.8 out of 20) than boys (15.5 to 15.9) during the same period (all p < 0.01). Regression analyses highlighted robust positive associations between PA and self-efficacy in those adhering to PA recommendations (i.e., physically active at least 5 times a week) and strong inverse associations for those reporting inactivity (never active) in both girls and boys from 2017 to 2021.

Conclusion

Adolescents in Norway report PA adherence ranging from 15 to 30%, with girls consistently exhibiting lower adherence to PA recommendations and reporting lower self-efficacy than boys. Notably, there are substantial associations between self-efficacy and both adherence to PA recommendations and inactivity over time. These findings underscore the significance of promoting adherence to PA recommendations during adolescence, especially among girls. Policymakers in Norway should focus on initiatives to increase PA levels among adolescents in both lower and upper secondary schools.

Predictors of Physical Activity Behavior Transitions in Children and Adolescents: A Systematic Review Based on a Transtheoretical Model

Background

The transtheoretical model (TTM) views individual behavioral change as a nonlinear, dynamic process, which is consistent with the complex nature of physical activity (PA) in children and adolescents. However, within this theoretical framework, the elements that facilitate the behavioral change in PA in children and adolescents need to be further explored.

Objective

A systematic review of research related to TTM-based exploration of the elements of behavioral change in PA in children and adolescents, an analysis of the strengths and weaknesses in practice, and an outlook for future research.

Materials and Methods

After computer searches of the CNKI, Wan-Fang, VIP, WOS, PubMed, and EBSCO databases, two researchers independently screened articles, extracted information, and evaluated the quality of the articles.

Results

A total of 25 articles (26 studies) of medium- to high-quality were included in the systematic review. The meta-analysis included 30,106 children and adolescents aged 11.24 to 17.7 years. The counter-conditioning and self-liberation of the process of change, self-efficacy and decisional balance are key elements that facilitate the transition of the PA stage in children and adolescents. Extramodel psychological variables such as exercise motivation play a moderate to large role in the PA stage transition. In addition, VPA is an important discriminator of PA stage transition in children and adolescents.

Conclusion

It is recommended that interventions be designed according to the key elements of behavioral change in order to better facilitate the PA stage transition of children and adolescents.

The Transtheoretical Model based psychoeducation's effect on healthy lifestyle behaviours in schizophrenia: A randomized controlled trial

OBJECTIVE

The study was conducted with the pretest-posttest randomized controlled trial design to detect the psychoeducation's effect, based on the Transtheoretical Model, on the healthy lifestyle behaviours of individuals with schizophrenia.

METHODS

The data were collected from 82 participants, as 41 intervention and 41 control. The data were collected via personal information form, behavioural change stage diagnosis form and healthy lifestyle scale II. 6-week psychoeducation, consisting of 6 modules, based on the Transtheoretical Model, was applied to the intervention group. No interventions were applied to the control group. Pretests and posttests were applied to both groups.

RESULTS

When the healthy lifestyle scale II of intervention and control groups and final test results arranged according to ANCOVA analysis are compared, average final test results were meaningfully positive for the intervention group with taking control of the pretest and other covariants. When the pretest-posttest results in terms of behavioural change of the intervention group are evaluated; a meaningful difference among nutrition, physical exercises, spiritual self-improvement and stress management, which all are the stages of behavioural change, was detected.

CONCLUSION

It was determined that psychoeducation on a healthy lifestyle, based on the Transtheoretical Model in an individual with schizophrenia affected physical exercises, spiritual self-improvement and interpersonal relationships sub-dimension in medium level, and had a drastic influence on health responsibility, nutrition, stress management sub-dimensions and all healthy lifestyle behaviours. Progress in behavioural change stages was detected.

CLINICAL TRIALS ID

NCT05259748.

Understanding farmers' conservation behavior over time: A longitudinal application of the transtheoretical model of behavior change

Global waterbodies are experiencing increased risk of eutrophication and harmful algal blooms due to excess nutrients including phosphorus and nitrogen discharged from human activity on the landscape and as a result of climate change. Despite modeling that suggests the efficacy of best management practices in agricultural systems to be sufficient to address the problem, adoption by farmers remains far below the levels needed to achieve significant water quality improvements and new approaches to encourage and sustain adoption are urgently needed. In this work, we apply a modified transtheoretical model (TTM) of behavior change to a longitudinal dataset (N = 584) of farmers' adoption decisions and stated intentions to use cover crops, collected in the Maumee Basin of Lake Erie, USA in 2016 and 2018. The TTM posits that behavior changes over time and is influenced by different social-psychological processes at each stage of change. Our findings confirm past research into the importance of many of the factors investigated, while providing new insight into their role in specific stages of the change process with potential implications for the design of interventions for farmers in different stages. Several factors investigated (mean environmental concern, education, information from conservation groups and off-farm income) were uniquely important to a particular stage. Other factors (response efficacy at the field level, total farm size and risks of spring planting interference) were important at both an earlier and later stage, but less important in predicting middle stages of change. A third set of factors (self-efficacy, proportion rented, no-till adoption and uncertain long-term paybacks) were statistically important across each stage of the TTM model. In applying the TTM longitudinally, we found evidence that farmers in a more advanced stage of cover crop adoption, in the first wave of data collection (2016) were more likely to have adopted cover crops in the second wave (2018), a result not predicted by individual factors alone. We report findings for cover crops but see the potential for the transtheoretical model of behavior change to be applied to other best management practice adoption decisions and to diverse populations of farmers to generate similarly novel insight and utility for intervention design and targeting.

Change in college student health and well-being profiles as a function of the COVID-19 pandemic

OBJECTIVE

The COVID-19 pandemic has potential for long-lasting effects on college students' well-being. We examine changes from just before to during the pandemic in indicators of health and well-being and comprehensive profiles of health and well-being, along with links between covariates and profiles during the pandemic.

PARTICIPANTS

1,004 students participated in a longitudinal study that began in November 2019.

METHODS

Latent class analysis identified health and well-being profiles at both waves; covariates were included in relation to class membership.

RESULTS

Mental health problems increased, whereas substance use, sexual behavior, physical inactivity, and food insecurity decreased. Six well-being classes were identified at each wave. Baseline class membership, sociodemographic characteristics, living situation, ethnicity, coping strategies, and belongingness were associated with profile membership at follow-up.

CONCLUSIONS

COVID-19 has had significant and differential impacts on today's students; their health and well-being should be considered holistically when understanding and addressing long-term effects of this pandemic.

Methylphenidate significantly improves neurocognitive impairments in children with ADHD

This study aimed to investigate the effects of methylphenidate (MPH) on scores on a neurocognitive test battery for individuals with various presentations of attention deficit/hyperactivity disorder (ADHD) and the effect of comorbidities on executive function. This study included 861 children and adolescents aged 7-17 years who were diagnosed with ADHD according to DSM-V criteria. The CNS Vital Signs Battery was utilized to compare the neuropsychological characteristics and MPH treatment responses of patients with predominantly inattentive (ADHD-I) and combined (ADHD-C) presentations of ADHD. Before MPH administration, a statistically significant difference was observed between groups only for complex attention. In addition, the overall prevalence rate of psychiatric comorbidities was 45.5%, and no statistically significant differences were found in the ADHD-I group pre- versus post-MPH administration. Prior to the administration of MPH, statistically significant differences were observed within the ADHD-C group between those with or without comorbidities. However, after MPH administration, these differences between the groups disappeared. The effects of MPH on improving scores on neuropsychological subtests were similar between the groups with different presentations of ADHD. Additionally, MPH treatment was effective despite the presence of comorbidities.

Reactivity to UV Radiation Exposure Monitoring Using Personal Exposure Devices for Skin Cancer Prevention: Longitudinal Observational Study

BACKGROUND

Emerging UV radiation (UVR) monitoring devices may present an opportunity to integrate such technology into skin cancer prevention interventions. However, little is known about the effects of using a wearable UVR monitor on adults' and children's sun protection-related behaviors and attitudes (eg, cancer worry and perceived risk). Understanding the potential role of reactivity and seasonal effects will help inform the use of objective monitors in the context of skin cancer prevention research, including intervention studies.

OBJECTIVE

The aim of this study is to examine the potential reactivity associated with a wearable personal UVR monitor, specifically the effects associated with reported sun-protective behaviors and skin cancer-related attitudes, which are often the targets of skin cancer preventive interventions.

METHODS

Child-parent dyads (n=97 dyads) were asked to wear a UVR monitoring device during waking hours for 2 weeks. Participants were asked to sync the device daily with a smartphone app that stored the UVR exposure data. Participants were blinded to their UVR exposure data during the 2-week period; thus, the smartphone app provided no feedback to the participants on their UVR exposure. Participants completed self-report questionnaires assessing sun-protective behaviors, sunburn, tanning, skin self-examination, skin cancer-related knowledge, perceived risk, cancer worry, response efficacy, and intentions to change behaviors over the 2-week period. Linear regressions were conducted to investigate changes in the outcomes over time and to account for the role of the season of study participation.

RESULTS

Regression results revealed that there was a significant decrease over time for several sun protection outcomes in children, including time spent outdoors on weekends (P=.02) and weekdays (P=.008), sunscreen use (P=.03), reapplication (P<.001), and unintentional tanning (P<.001). There were no significant changes over time in children's and parents' UVR exposure, sunburn occurrence, or sun protection attitudes. Season of participation was associated with several outcomes, including lower sunscreen use (P<.001), reapplication (P<.001), sunburns (P=.01), intentions to change sun-protective behaviors (P=.02), and intentional (P=.008) and unintentional tanning (P=.01) for participants who participated in the fall versus the summer.

CONCLUSIONS

The findings from this study suggest that daily use of a UVR monitoring device over a 2-week period may result in changes in certain sun-protective behaviors. These results highlight the importance of identifying and addressing potential reactivity to UVR monitoring devices, especially in the context of skin cancer preventive intervention research. Ultimately, objectively assessed UVR exposure could be integrated into the outcome assessment for future testing of skin cancer prevention interventions.

Predictors of physical activity behavior change based on the current stage of change-an analysis of young people from Hawai'i

This study investigated the corresponding change between psycho-social predictors and physical activity (PA) behavior and if these relationships were dependent on the stages of change from the Transtheoretical Model in Minority American adolescents. We conducted a longitudinal field study with N = 357 students aged 13-18 years (M = 14.24 years, SD = 0.88); predominantly Filipino (61.2%) using a test-retest design assessing psycho-social PA predictors (enjoyment, self-efficacy, family support, friends' support, knowledge, stage of change) and moderate-to-vigorous physical activity (MVPA) at two time points over six months. Hierarchical regression results indicated that a positive change of enjoyment, knowledge about PA and family support predicted a change of MVPA, independently of stage. The time-varying covariation showed the importance of the current stage of change for enjoyment, self-efficacy and support of friends for a change of MVPA. Overall, our findings suggest that an individual's current stage of change should be considered to determine individually appropriate starting points and goals for designing interventions to promote PA among Minority American adolescents.

The Relationship Between Self-Regulatory Efficacy and Physical Activity in Adolescents With a Caveat: A Cross-Lag Design Examining Weather

PURPOSE

The use of self-efficacy to predict physical activity has a long history. However, this relationship is complex, as self-efficacy is thought to influence and be influenced by physical activity. The directionality of the self-regulatory efficacy (SRE) and physical activity relationship was examined using a cross-lagged design. A secondary purpose was to examine these relationships across differing weather conditions.

METHODS

Canadian adolescents (N = 337; aged between 13 and 18 years) completed the physical activity and SRE measures 4 times during a school year. Structural equation modeling was used to perform a cross-lag analysis.

RESULTS

The relationships between physical activity and SRE appeared to be weather dependent. During a more challenging weather period (eg, cold weather), the relationship between physical activity and SRE was bidirectional. However, no relationship emerged when the 2 constructs were assessed during a more optimal weather period (eg, warm weather).

CONCLUSIONS

Some support has been provided for the bidirectional nature of the relationship between physical activity and SRE. The relationship appeared to be qualified by climate considerations, suggesting that future research examine how weather may relate not just to physical activity but also to the correlates of physical activity.

Temporal Sequencing of Physical Activity Change Constructs within the Transtheoretical Model

OBJECTIVE

Studies support the Transtheoretical Model's (TTM) ability to describe behavior change processes and guide interventions; however, the temporal sequencing of constructs is less understood. This cohort study tested five sequences to identify TTM construct changes related to physical activity.

METHODS

A random sample provided baseline data (n=689; 63% female; M _age (SD)=47(17); 37% white), with 401 participants providing 24-month data, at six-month intervals.

RESULTS

Structural equation models revealed processes to cognitions to stage (AIC=29313.093, BIC=29514.883, CFI=0.999, RMSEA=0.006, SRMR=0.026); processes to stage to cognitions (AIC=27788.651, BIC=27973.268, CFI=0.978, RMSEA=0.024, SRMR=0.038), self-efficacy/temptations to processes to decisional balance to stage (AIC=13914.771, BIC=14031.169, CFI=0.981, RMSEA=0.018, SRMR=0.034), and stage to processes to cognitions (AIC=22048.324, BIC=22212.986, CFI=0.976, RMSEA=0.026, SRMR=0.029) all fit well. However, cognitions to processes to stage did not fit the data well (AIC=10353.555, BIC=10444.179, CFI=0.937, RMSEA=0.038, SRMR=0.035).

CONCLUSIONS

Integrating results revealed a cyclical model so that intervention efforts should focus on processes to change cognitions related to barrier self-efficacy and decisional balance, which then lead to change in stage and then renew focus on the processes.

Biological/Genetic Regulation of Physical Activity Level: Consensus from GenBioPAC

PURPOSE

Physical activity unquestionably maintains and improves health; however, physical activity levels globally are low and not rising despite all the resources devoted to this goal. Attention in both the research literature and the public policy domain has focused on social-behavioral factors; however, a growing body of literature suggests that biological determinants play a significant role in regulating physical activity levels. For instance, physical activity level, measured in various manners, has a genetic component in both humans and nonhuman animal models. This consensus article, developed as a result of an American College of Sports Medicine-sponsored round table, provides a brief review of the theoretical concepts and existing literature that supports a significant role of genetic and other biological factors in the regulation of physical activity.

CONCLUSIONS

Future research on physical activity regulation should incorporate genetics and other biological determinants of physical activity instead of a sole reliance on social and other environmental determinants.

Irresponsible Research and Innovation? Applying Findings from Neuroscience to Analysis of Unsustainable Hype Cycles

The introduction of technological innovations is often associated with suboptimal decisions and actions during cycles of inflated expectations, disappointment, and unintended negative consequences. For brevity, these can be referred to as hype cycles. Hitherto, studies have reported hype cycles for many different technologies, and studies have proposed different methods for improving the introduction of technological innovations. Yet hype cycles persist, despite suboptimal outcomes being widely reported and despite methods being available to improve outcomes. In this communication paper, findings from exploratory research are reported, which introduce new directions for addressing hype cycles. Through reference to neuroscience studies, it is explained that the behavior of some adults in hype cycles can be analogous to that of irresponsible behavior among adolescents. In particular, there is heightened responsiveness to peer presence and potential rewards. Accordingly, it is argued that methods applied successfully to reduce irresponsible behavior among adolescents are relevant to addressing hype cycles, and to facilitating more responsible research and innovation. The unsustainability of hype cycles is considered in relation to hype about artificial intelligence (AI). In particular, the potential for human-beneficial AI to have the unintended negative consequence of being fatally unbeneficial to everything else in the geosphere other than human beings.

One-year changes in physical activity and sedentary behavior among adolescents: the Croatian Physical Activity in Adolescence Longitudinal Study (CRO-PALS)

Background Little is known about the concurrent change in physical activity (PA), sedentary behavior (SB) and sport participation (SP) during adolescence. The main purpose of this prospective and partly objective study was to simultaneously investigate PA, SBs and SP changes between the 1st and 2nd grades of high school in urban adolescents. Methods In this 1-year follow-up study, the participants were 81 secondary-school students (28 boys and 53 girls) aged 15.5 years at the baseline. PA was assessed with the SenseWear Armband multi-sensor activity monitor, while SBs were assessed by using School Health Action, Planning and Evaluation System (SHAPES) PA questionnaire. The SHAPES questionnaire was supplemented with two questions inquiring about SP in organized sports in school and outside of school. Results PA decreased markedly in both genders between the 1st and 2nd grades of high school. Total energy expenditure (TEE) was reduced by 13 kcal/kg/day on average in boys and by 10 kcal/kg/day in girls (p for both <0.001), while mean daily active energy expenditure (AEE) decreased by 7 kcal/kg/day (p < 0.001) and 3 kcal/kg/day (p = 0.04) in boys and girls, respectively. Similarly, the amount of moderate PA declined by 49 min/day in boys and 21 min/day in girls (p for both <0.001). At the same time vigorous PA was cut by 14 min/day (p < 0.001) and 3 min/day (p = 0.003) in boys and girls, respectively. Conversely, time spent in SBs did not show any change. Conclusion In conclusion, a decline in PA between the 1st and 2nd grades of high school was marked but was not accompanied with an increase in SBs. Policies aimed at increasing PA should be targeting the period of entering secondary school to offset the observed drop in PA.

Comparison of Neurological and Cognitive Deficits in Children With ADHD and Anxiety Disorders

OBJECTIVE

To compare the neuro-cognitive profiles among initial clinic referred medication naive sample of children with anxiety disorders (ANXs) and ADHD in a youth sample.

METHOD

Three groups of patients, ANX ( n = 40), ADHD ( n = 48), and ANX + ADHD ( n = 33), aged 7 to 12 years, were compared with respect to their Physical and Neurological Examination for Subtle Signs (PANESS) and cognitive measures (digit span, digit symbol, Trail Making Test [TMT]-A and TMT-B, Stroop test).

RESULTS

ADHD group performed worse than the other two groups with regard to soft signs and cognitive test performance; ANX + ADHD were impaired relative to ANX but better than ADHD. Significant differences were found for gait and station problems, overflows and timed movements, TMT error points, and Stroop interference scores. ADHD patients had more difficulty in warding off irrelevant responses and lower speed of time-limited movements.

CONCLUSION

This clinical evaluation study suggested that ANX and ADHD seem to have significantly different neuro-cognitive features: Poorest outcomes were observed among children with ADHD; rather than problems of attention, inhibitory control deficits were the most prominent differences between ANX and ADHD; and the presence of ANX appears to have mitigating effect on ADHD-related impairments.

Heritability of the affective response to exercise and its correlation to exercise behavior

OBJECTIVES

Individual differences in adolescent exercise behavior are strongly influenced by genetic factors. The affective response to exercise is a potential source of these genetic influences. To test its role in the motivation to exercise, we estimated the heritability of the affective responses during and after exercise and the overlap with the genetic factors influencing regular voluntary exercise behavior.

DESIGN

226 twin pairs and 38 siblings completed two submaximal exercise tests on a cycle ergometer and a treadmill and a maximal exercise test on a cycle ergometer. Affective responses were assessed by the Feeling Scale (FS), Borg's Rating of Perceived Exertion (RPE) and the Activation-Deactivation Adjective Checklist (AD ACL).

METHODS

Multivariate structural equation modeling was used to estimate heritability of the affective responses during and after submaximal and maximal exercise and the (genetic) correlation with self-reported regular voluntary exercise behavior over the past year.

RESULTS

Genetic factors explained 15% of the individual differences in FS responses during the cycle ergometer test, as well as 29% and 35% of the individual differences in RPE during the cycle ergometer and treadmill tests, respectively. For the AD ACL scales, heritability estimates ranged from 17% to 37% after submaximal exercise and from 12% to 37% after maximal exercise. Without exception, more positive affective responses were associated with higher amounts of regular exercise activity (.15 < r < .21) and this association was accounted for by an overlap in genetic factors influencing affective responding and exercise behavior.

CONCLUSIONS

We demonstrate low to moderate heritability estimates for the affective response during and after exercise and significant (genetic) associations with regular voluntary exercise behavior. These innate individual differences in the affective responses to exercise should be taken into account in interventions aiming to motivate adolescents to adopt and maintain regular exercise.

[Prevention of overweight and obesity in children and adolescents : Critical appraisal of the evidence base]

BACKGROUND

Despite careful planning and implementation, overweight/obesity prevention interventions in children and adolescents typically show no, inconsistent or merely weak effects. Such programs usually aim at behavior changes, rarely also at environmental changes, that draw upon conventional wisdom regarding the commonly accepted determinants of childhood overweight/obesity.

OBJECTIVE

This paper evaluates the evidence base of the apparently overweight-/obesity-related determinants diet, physical activity and stress. The results of international intervention studies are discussed against this background.

METHODS AND MATERIALS

Based on the mediating-moderating variable model, we investigate the effect of theory specified mediating variables and how potential moderating variables may impact these relationships.

RESULTS

Contrary to common beliefs, recent research has revealed inconsistent evidence regarding associations between potentially obesogenic behaviors and overweight/obesity in youth. Moreover, the evidence for strong and causal relationships between mediating variables and targeted behaviors seems to be inconsistent. In addition, inadequate attention is paid to moderating effects.

DISCUSSION

The etiology of overweight/obesity in youth is likely the result of a complex interplay of multi-causal influences. Future prevention interventions would benefit from a more thorough understanding of the complex relationships that have been hypothesized and of the mechanisms of suspected behaviors for affecting overweight/obesity. Only if substantial change can be demonstrated in mediators with reasonable effort under real world circumstances, it will make sense to progress to community behavior change trials.

An application of Dirichlet process in clustering subjects via variance shift models: A course-evaluation study

In this article, the Dirichlet process (DP) is applied to cluster subjects with longitudinal observations. The basis of clustering is the ability of subjects to adapt themselves to new circumstances. Indeed, the basis of clustering depends on the time of changing response variability. This is done by providing a random change-point time in the variance structure of mixed-effects models. The DP is assumed as a prior for the distribution of the random change point. The discrete nature of the DP is utilized to cluster subjects according to the time of adaption. The proposed model is useful to identify groups of subjects with distinctive time-based progressions or declines. Transition mixed-effects models are also used to account for the serial correlation among observations over time. A joint modelling approach is utilized to handle the bias created in these models. The Gibbs sampling technique is adopted to achieve parameter estimates. Performance of the proposed method is evaluated via conducting a simulation study. The usefulness of the proposed model is assessed on a course-evaluation dataset.

The effect of transtheoretical model-based individual counseling, training, and a 6-month follow-up on smoking cessation in adult women: a randomized controlled trial

BACKGROUND/AIM

This study was conducted to determine the effect of transtheoretical model (TTM)-based individual counseling, training, and a 6-month follow-up on smoking cessation in adult women.

MATERIALS AND METHODS

We carried out this randomized controlled trial in Konya, Turkey. Female subjects were randomly assigned into groups in a 1:1 ratio using block randomization, block size 3 × 3, divided by stages (precontemplation, contemplation, and preparation) and age (20-29, 30-39, and 40-49 years). The study was completed with 77 women (an intervention group containing 38 participants and a control group of 39 participants). The intervention group was interviewed 5 times (baseline and 1, 1.5, 2, and 6 months). Counseling and training were given to the intervention group at the first 3 interviews. The TTM scales were assessed for both groups at baseline and at 2 and 6 months.

RESULTS

In the 6-month follow-up, the rate of smoking cessation and the rate of progress were higher in the intervention group than in the control group. All the TTM variables had differences except the cognitive processes in the intervention group over time. Analysis of variance related to time × groups indicated that all variables had significantly changed except the cognitive processes and the pros of change.

CONCLUSION

Results suggest that the TTM may be useful in understanding the stages individuals are at and in deciding on the appropriate treatment for smoking cessation.

Effectiveness of a school-community linked program on physical activity levels and health-related quality of life for adolescent girls

BACKGROUND

This study evaluated the effectiveness of a school-community program on Health-Related Quality of Life (HRQoL; the primary outcome), physical activity (PA), and potential mediators of PA among adolescent girls living in low-socioeconomic rural/regional settings.

METHOD

The study was a cluster-randomized controlled trial. Twelve communities with the requisite sports clubs and facilities were paired according to relevant criteria; one of each pair was randomly assigned to the intervention or control condition. Eight schools per condition were randomly selected from these communities and the intervention was conducted over one school year (2011). Female students in grades 7-9 in intervention schools participated in two 6-session PA units - a sport unit (football or tennis) and a recreational unit (leisure centre-based). These were incorporated into physical education (PE) curriculum and linked to PA opportunities for participation outside school. Students were surveyed at baseline and endpoint, self-reporting impact on primary and secondary outcome measures (HRQoL, PA) and PA mediators (e.g. self-efficacy). Linear mixed models for two-group (intervention, control) and three-group (completers, non-completers, control) analyses were conducted with baseline value, age and BMI as covariates, group as a fixed effect and school as random cluster effect.

RESULTS

Participants completing baseline and endpoint measures included: 358 intervention (baseline response rate 33.7%, retention rate 61.3%) and 256 control (14.1% and 84.0%). Adjustment for age and BMI made no substantive difference to outcomes, and there were no cluster effects. For HRQoL, after adjustment for baseline scores, the intervention group showed significantly higher scores on all three PedsQL scores (physical functioning: M ± SE = 83.9 ± 0.7, p = .005; psychosocial: 79.9 ± 0.8, p = .001; total score: 81.3 ± 0.7, p = .001) than the control group (80.9 ± 0.8; 76.1 ± 0.9 and 77.8 ± 0.8). The three-group analysis found intervention non-completers had significantly higher PedsQL scores (84.0 ± 0.8, p = .021; 80.4 ± 0.9, p = .003; 81.7 ± 0.8, p = .002;) than controls (80.9 ± 0.8, 76.1 ± 0.9 and 77.8 ± 0.8). There were no significant differences for any PA measure. Intervention completers had significantly higher scores than non-completers and controls for some mediator variables (e.g. self-efficacy, behavioural control).

CONCLUSION

Positive outcomes were achieved from a modest school-community linked intervention. The school component contributed to maintaining HRQoL; students who completed the community component derived a range of intra-personal and inter-personal benefits.

TRIAL REGISTRATION

ACTRN12614000446662. April 30th 2014.

Does the transtheoretical model of behavior change provide a useful basis for interventions to promote fruit and vegetable consumption?

PURPOSE

To determine whether Transtheoretical Model (TTM) constructs differ between individuals making successful versus unsuccessful stage transitions for consumption of five or more servings of fruit and vegetables each day and thus provide a useful basis for designing health promotion interventions.

DESIGN

Longitudinal, observational study. A randomly selected, multiethnic cohort of adults assessed at 6-month intervals over 2 years.

SETTING

General community, Hawaii.

SUBJECTS

There were 700 participants (62.6% female; mean = 47 ± 17.1 years; 31.1% Asian, 22.1% Native Hawaiian/Pacific Islander, 35.0% Caucasian; 25.1% participation rate).

MEASURES

Stage of readiness, experiential and behavioral processes of change, pros, cons, self-efficacy, and self-reported fruit and vegetable consumption.

ANALYSIS

The study used t-tests to determine which TTM variable scores differed consistently between those making "successful" versus "unsuccessful " stage transitions from precontemplation, preparation, and maintenance. Sample sizes for contemplation and action prohibited similar analyses.

RESULTS

Compared to those remaining in precontemplation, individuals successfully progressing from precontemplation showed significantly greater use of behavioral processes (collectively and self-liberation) and consciousness raising (p < .001). However, only self-liberation demonstrated significant differences consistently over time.

CONCLUSION

This longitudinal investigation reveals that TTM behavioral processes, particularly self-liberation, predict successful transition out of precontemplation for adult fruit and vegetable consumption, suggesting that public health messages tailored according to these TTM variables may be effective for this group. However, for adults prepared to adopt or maintain fruit and vegetable consumption, tailoring based on variables from other theories is needed.

Impact of physical activity intervention programs on self-efficacy in youths: a systematic review

Lack of physical activity has contributed to the nation's childhood obesity crisis, but the impact of physical activity on self-efficacy as a mediator of behavior change has not been examined. This systematic review (SR) describes the published evidence related to the impact of physical activity intervention programs on self-efficacy among youths. From January 2000 to June 2011, the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) standards were used to identify publications from PubMed, PsychInfo, Web of Knowledge, and the Cochran Database of Systematic Reviews. The Cochrane Population, Intervention, Control, Outcome, Study Design (PICOS) approach guided this SR articles selection and evaluation process. Of the 102 publications screened, 10 original studies matched the SR inclusion criteria. The types of physical activity interventions and self-efficacy assessments for these 10 studies were diverse. Of the 10 included articles, 6 articles identified an improvement in post-self-efficacy assessments compared to baseline and 4 showed no effect. In conclusion, physical activity intervention programs may improve self-efficacy in youths. A standardized approach to classify and measure self-efficacy is required. Further research is needed to quantify the association of self-efficacy ratings after completing physical activity interventions with objective health improvements, such as weight loss.

Changes in social-cognitive variables are associated with stage transitions in physical activity

When it comes to the adoption or maintenance of physical activity, individuals can be placed along a continuum or into stages of change. The Health Action Process Approach proposes three such stages: non-intentional, intentional and actional. Intraindividual differences are reflected by stage transitions: either progression or regression. The present study examines social-cognitive factors of stage transitions: outcome expectancies, self-efficacy and planning. In an online study on physical activity, 660 adults completed questionnaires at baseline and approximately 3 weeks later. Social-cognitive factors were converted into standardized residual change scores to account for changes in outcome expectancies, self-efficacy and planning within the observation period. Discriminant function analyses revealed stage-specific patterns: progression out of non-intentional stage was associated with self-efficacy increases. Out of intentional stage, regression was correlated with decreases in planning, whereas progression was linked to increases in self-efficacy and planning. Regression from action stage was associated with decreases in self-efficacy. Physical activity promotion should focus on improving self-efficacy for non-intending, intending and acting individuals, whereas planning interventions are recommended for intending individuals. Interventions may be more effective by considering specific mechanisms instead of providing generic interventions for all individuals at different stages.

Physical activity change during adolescence: a systematic review and a pooled analysis

BACKGROUND

It is presumed that physical activity (PA) level declines during the lifespan, particularly in adolescence. However, currently, there is no study that quantifies these changes and pools results for a common interpretation. Therefore, the purpose was to systematically review the international literature regarding PA change during adolescence, and to quantify that change according to a series of study variables, exploring gender-and-age differences.

METHODS

An electronic search was conducted in the Medline/PubMed and Web of Science databases. Longitudinal studies with, at least, two PA measures throughout adolescence (10-19 years old) or the first PA measure during childhood and the second one during adolescence were selected. From each article, study project name, country, year of the first data collection, sample size, baseline age, follow-up duration, characteristics of the instrument (type, recall time, PA intensity and PA domain), unit of PA measure and report of statistical significance were collected.

RESULTS

Overall, 26 studies matched the inclusion criteria. Most were carried out in the USA, assessed PA by questionnaire, and found a decline in PA levels during the adolescence. On average, the mean percentage PA change per year, across all studies, was -7.0 (95% confidence interval: -8.8 to -5.2), ranging from -18.8 to 7.8. The decline was significant according to most sub-groups of variables analysed. Although earlier studies revealed a higher PA decline in boys, the decline has been greater in girls in more recent studies (commenced after 1997). Moreover, although the decline among girls was higher in younger ages at baseline (9-12 years), it was higher in older ages (13-16 years) among boys.

CONCLUSIONS

The decline of PA during adolescence is a consistent finding in the literature. Differences between boys and girls were observed and should be explored in future studies. Interventions that attempt to attenuate the PA decline, even without an increase in PA levels, could be considered as effective.

Using constructs of the transtheoretical model to predict classes of change in regular physical activity: a multi-ethnic longitudinal cohort study

Explaining variation in meeting recommended levels of physical activity across time is important for the design of effective public health interventions. To model longitudinal change in constructs of the Transtheoretical Model and test their hypothesized relations with change in meeting the Healthy People 2010 guidelines for regular participation in moderate or vigorous physical activity, a cohort (N = 497) from a random, multi-ethnic sample of 700 adults living in Hawaii was assessed at 6-month intervals three or more times for 2 years. Latent class growth modeling was used to classify people according to their initial levels and trajectories of change in the transtheoretical variables and separately according to whether they met the physical activity guideline each time. Relations of the variables and their change with classes of meeting the guideline were then tested using multinomial logistic regression. Despite declines or no change in mean scores for all transtheoretical variables except self-efficacy, participants who maintained or attained the physical activity guideline were more likely to retain higher scores across the 2 years of observation. The usefulness of transtheoretical constructs for predicting maintenance of, or increases in, public health levels of physical activity was generally supported. These longitudinal results support earlier cross-sectional findings which indicate that, contrary to theory, people appear to use both experiential and behavioral processes while they attempt to increase or maintain their physical activity.

Prediction of Physical Activity Intention and Behavior in a Longitudinal Sample of Adolescent Girls

The purpose of the present study was to investigate a theory of planned behavior model for the prediction of physical activity in adolescent girls using a 1-yr. longitudinal design. A secondary purpose was to examine the moderating influence of intention stability and past behavior on intention-behavior relationships. Participants were 236 12- to 13-year-old adolescent girls who completed measures of the theory of planned behavior and physical activity participation (3-Day Physical Activity Recall) across a 1-yr. interval. The standard theoretical variables predicted intentions, as intention, past behavior, and perceived behavioral control predicted behavior. The temporal stability of intentions and past behavior moderated relationships between intention and behavior. An autoregressive path model showed that intention and perceived behavioral control predicted changes in physical activity and physical activity predicted changes in intention, affective attitude, and perceived behavioral control. This study supports the use of the theory of planned behavior in gaining an understanding of the physical activity intention and behavior of adolescent girls.

Mediators of physical activity behavior change: a multivariate approach

OBJECTIVE

Using a multivariate extension of the Baron and Kenny (1986) mediation framework, we examined the simultaneous effect of variables hypothesized to mediate the relationship between a motivationally tailored physical activity intervention, and 6-month physical activity behavior in 239 healthy, underactive adults (M age = 47.5; 82% women).

DESIGN

Participants were randomly assigned to (a) print-based feedback; (b) telephone-based feedback; or (c) contact control.

MAIN OUTCOME MEASURES

Psychosocial variables, including self-efficacy, decisional balance, and processes of change.

RESULTS

All mediation criteria were satisfied for both intervention arms. A moderate indirect effect of print (0.39, 95% CI = 0.21, 0.57) was found due to increases in behavioral processes (0.54, 95% CI = 0.29, 0.80) being attenuated by decreases due to cognitive processes (-0.17, 95%CI = 0.31,-.03). A moderate indirect effect was observed for telephone (0.47, 95% CI = 0.28, 0.66), with increases due to behavioral processes (0.61, 95% CI = 0.34, 0.87) attenuated by decreases due to cognitive processes (0.15, 95% CI = -0.27, -0.02); self-efficacy and decisional balance mediational paths did not attain statistical significance.

CONCLUSIONS

These findings highlight the importance of studies that deconstruct the theoretical components of interventions to determine which combination produces the greatest behavior changes at the lowest cost.

Factors associated with transitional shifts in college students' physical activity behavior

The Transtheoretical Model (Prochaska & Marcus, 1994) has been widely used as a framework for understanding exercise behavior change. The purpose of this study was to clarify equivocal research findings reported for model predictions when examining stage movement over time rather than static stages and to provide some evidence of the construct validity of transitional stages. Participants were female (n = 285) and male (n = 243) undergraduates (M age = 19.9 years, SD = 2.7) who completed previously validated questionnaires twice, separated by 9 weeks, that assessed stage of change, exercise behavior, processes of change, pros and cons of exercise, and exercise self-efficacy. Participants were classified into one of five transitional shift groups based on their responses at baseline and follow up: (a) stable sedentary, (b) stable active, (c) activity adopters, (d) activity relapsers, and (e) perpetual preparers. Results of a 5 (group) x 2 (time) repeated measures (RM) analysis of variance (ANOVA) examining exercise behavior revealed a significant interaction (p < .001) and supported transitional stage classification, with activity adopters and stable actives increasing exercise over time and relapsers decreasing activity. Separate 5 (group) x 2 (time) RM ANOVAs examining model constructs revealed no significant interaction for cognitive processes of change; however, activity adopters and stable actives reported significant (p < .01) increases in the use of behavioral processes over time, while only the activity relapsers and perpetual preparers reported decreases. Activity relapsers also reported significant (p < .05) decreases in the pros of exercise. No significant interactions were found for the cons of exercise behavior. Unlike findings reported in cross-sectional studies, increases in self-efficacy did not accompany increases in exercise stage. The findings strongly support examination of stage movement classifications rather than static stages, as these transitions provide greater insight into the mechanisms of exercise behavior change.

Crisis and chaos in behavioral nutrition and physical activity

Resnicow & Vaughn challenged the field of behavioral nutrition and physical activity to conduct research in new ways. They challenged the predictiveness of our models, sensitivity to initial conditions, factors predisposing to change and measurement procedures. While the predictiveness of our models will reflect the sophistication of our thinking and research, and the sensitivity to initial conditions is subsumed under the sophistication of our models, research on conditions predisposing to change (e.g. epiphanies), more longitudinal designs, refined measurement procedures and testing of critical issues can only enhance the quality of our research. Improved research quality should lead to enhanced efficacy and effectiveness of our interventions, and thereby our making meaningful contributions to mitigating the chaos in our field and the crisis from the rising epidemic of obesity.

Do the Transtheoretical Processes of Change Predict Transitions in Stages of Change for Fruit Intake?

In a longitudinal study, it is examined whether the transtheoretical processes of change do predict stage transitions in fruit intake. A random sample of an existing Internet research panel resulted in a cohort of 735 adults, who were examined three times with electronic questionnaires assessing stages of change, processes of change, and fruit intake. Cross-sectional differences were found for the processes of change between precontemplation and all further stages. Experiential as well as behavioral processes increased from precontemplation to action with similar patterns. Both experiential and behavioral processes predicted forward transition out of precontemplation and forward transition into action, whereas only behavioral processes predicted forward transition out of contemplation. The results indicate that the transtheoretical processes of change predict stage transitions for fruit intake, but that the pattern of relevant processes for fruit intake is not as straightforward as outlined by the transtheoretical model of behavior change.

Applying the transtheoretical model to exercise: a systematic and comprehensive review of the literature

Three questions guided a literature review of the transtheoretical model (TTM) as applied to exercise to address the evidence for stage-matched interventions, the description of priority populations, and the identification of valid TTM measurement tools. One-hundredand-fifty studies were reviewed. Results indicate preliminary support for the use of stage-matched exercise interventions. Most studies have focused on White, middle-class, female populations, limiting the generalizability of their findings. Valid and reliable measures exist for stage of change, decisional balance, processes of change, self-efficacy, and temptations to not exercise; however, more research is needed to refine these measures. Evidence for the construct validity of the TTM as applied to exercise is mixed. When designing and implementing TTM-based exercise interventions, practitioners and policy makers are encouraged to clearly define the term exercise, choose a valid and reliable staging tool, and employ all TTM constructs and not just stage membership.

Predicting physical activity intention and behaviour among children in a longitudinal sample

We examined predictors of leisure-time physical activity intention and behaviour in children, and the potential direct and moderating effects of gender and ethnicity. Participants were 364 (230 Asian; 134 Caucasian) 9-11-year-old children who completed measures of the theory of planned behaviour (TPB) and physical activity behaviour (Physical Activity Questionnaire for Children) across three, 3-month intervals (i.e., two prediction time-periods) in Canada. The TPB explained 35-50% of the variance in physical activity behaviour and 74-76% of the variance in intention using structural equation modelling. An autoregressive longitudinal path model showed that the TPB predicted changes in physical activity and physical activity predicted changes in TPB constructs (p<.05). Overall, intention and perceived behavioural control were significant (p<.05) contributors to the direct prediction of behaviour and subjective norm and perceived behavioural control were significant (p<.05) predictors of intention. Gender did not show a robust relationship with physical activity or intention, but the effect of ethnicity on physical activity was mediated through perceived behavioural control (Asians less active than Caucasians). Finally, gender and ethnicity did not moderate TPB and physical activity relations (p<.05). These data suggest that childhood may be a formative stage for the development of physical activity cognitions and that promoting physical activity in children may require normative and control-based intervention.

Stages of change in adolescents: an examination of self-efficacy, decisional balance, and reasons for relapse

PURPOSE

The purpose of this study was to test selected constructs of the transtheoretical model (TTM) of behavior change in relation to exercise behavior with an adolescent sample. A further purpose was to examine reasons why adolescents stop physical activity and to relate these to stages of exercise change.

METHODS

Participants were 15 to 17 year old students at a private high school (N = 327). Participants completed a questionnaire consisting of an exercise measure, measures of the TTM variables, and an open-ended question that asked if they used to exercise in the past but currently did not, why they had stopped. The TTM data were analyzed using ANOVA F-tests with post-hoc Scheffe tests. To evaluate the ability of the TTM variables to discriminate between stages of exercise behavior, standard discriminant function analyses were performed. Open-ended answers to the relapse question were themed according to a model which categorizes barriers preventing youth's participation in recreational activities as infrastructural, superstructural, and procedural. The relationship of perceived barriers to stage of behavior change was assessed using cross-tabulation and chi-square analyses.

RESULTS

Moderate support for the TTM constructs were found, with the strongest discriminator between stages being strenuous exercise, and self-efficacy being the most supported construct. Infrastructural, superstructural, and procedural barriers were all evident.

CONCLUSION

Over 30% of previously active adolescents in this study reported barriers precluding extracurricular physical activity. Interventions should target the most often cited reasons for relapse: time and limits relating to the nature of the adolescent self.

Self-management strategies mediate self-efficacy and physical activity

BACKGROUND

Self-efficacy theory proposes that girls who have confidence in their capability to be physically active will perceive fewer barriers to physical activity or be less influenced by them, be more likely to pursue perceived benefits of being physically active, and be more likely to enjoy physical activity. Self-efficacy is theorized also to influence physical activity through self-management strategies (e.g., thoughts, goals, plans, and acts) that support physical activity, but this idea has not been empirically tested.

METHODS

Confirmatory factor analysis was used to test the factorial validity of a measure of self-management strategies for physical activity. Next, the construct validity of the measure was tested by examining whether self-management strategies mediated the relationship between self-efficacy and self-reported physical activity, independently of several social-cognitive variables (i.e., perceived barriers, outcome expectancy value, and enjoyment), among cross-sectional samples of 6th grade (n=309) and 8th grade (n=296) girls tested between February 14 and March 17, 2002. Data were analyzed in 2004.

RESULTS

Consistent with theory, self-efficacy had direct effects on the social-cognitive variables. The primary novel finding is that self-management strategies mediated the association of self-efficacy with physical activity in both samples.

CONCLUSIONS

The measure of self-management strategies for physical activity yields valid scores among adolescent girls and warrants experimental study as a mediator of the influence of efficacy beliefs on physical activity.

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.

Stage of change movement across three health behaviors: the role of self-efficacy

PURPOSE

In this study, we examined the influence of self-efficacy in predicting stage of change (SOC) movement, without intervention, over a 1-month period for smoking cessation, exercise adoption, and dietary fat reduction.

DESIGN

The design of this study was longitudinal. Patients' stage of change and self-efficacy were assessed at baseline, and stage of change was reassessed at a 1-month follow-up. Patients were categorized as (1) Regressors (moved backward at least one stage), (2) Stables (no change), or (3) Progressors (moved forward at least one stage). Chi-square analyses were used to determine the ability of self-efficacy to predict stage movement at 1-month follow-up.

SETTING

The data were collected at a large, inner city, academic hospital in the southeastern United States. Patients were attending primary care clinics.

SUBJECTS

Five hundred fifty-four low income, predominantly African-American, individuals attending primary care clinics were participants in the study.

MEASURES

Previously validated scales of stage of change and self-efficacy from Prochaska's laboratory were used in this study.

RESULTS

Results showed statistically significant differences between predicted and actual SOC movement for smoking cessation, exercise adoption, and dietary fat intake reduction. Baseline self-efficacy ratings were significantly related to stage progression, regression, and stability of stage of change for all three health behaviors. Thirty-seven percent of smokers who were predicted to progress on the basis of their self-efficacy scores progressed. For exercise adoption and dietary fat reduction, 50% and 44%, respectively, of individuals expected to progress at least one stage on the basis of self-efficacy scores progressed.

CONCLUSION

Self-efficacy influences SOC movement for smoking cessation, dietary fat reduction, and exercise adoption.

Cancer prevention among rural youth: building a "bridge" to better health with genealogy

BACKGROUND

The Bridge to Better Health (BRIDGE) project is a program that focuses on providing rural high school youth with motivation, knowledge, and skills essential to cancer prevention. In this pilot intervention, we used instruction in personal health genealogy as a means of increasing awareness and knowledge of health risk and motivation to change several screening and cancer-related behaviors.

METHODS

We administered a Bridge to Better Health survey to 173 ninth- and 10th-grade students from a rural Southeastern Virginia high school before and after delivery of the BRIDGE pilot intervention.

RESULTS

Significant preintervention to postintervention changes were observed for general genealogy knowledge, personal health genealogy, self-efficacy, and intention to practice self-examinations (breast, testicular, and skin) and eating a high-fiber and low-fat diet.

CONCLUSION

These project results demonstrate the importance of theory-driven interventions for increasing cancer knowledge and changing cancer-related dietary and screening behaviors.

Are current health behavioral change models helpful in guiding prevention of weight gain efforts?

Effective procedures are needed to prevent the substantial increases in adiposity that have been occurring among children and adults. Behavioral change may occur as a result of changes in variables that mediate interventions. These mediating variables have typically come from the theories or models used to understand behavior. Seven categories of theories and models are reviewed to define the concepts and to identify the motivational mechanism(s), the resources that a person needs for change, the processes by which behavioral change is likely to occur, and the procedures necessary to promote change. Although each model has something to offer obesity prevention, the early promise can be achieved only with substantial additional research in which these models are applied to diet and physical activity in regard to obesity. The most promising avenues for such research seem to be using the latest variants of the Theory of Planned Behavior and Social Ecology. Synergy may be achieved by taking the most promising concepts from each model and integrating them for use with specific populations. Biology-based steps in an eating or physical activity event are identified, and research issues are suggested to integrate behavioral and biological approaches to understanding eating and physical activity behaviors. Social marketing procedures have much to offer in terms of organizing and strategizing behavioral change programs to incorporate these theoretical ideas. More research is needed to assess the true potential for these models to contribute to our understanding of obesity-related diet and physical activity practices, and in turn, to obesity prevention.

Older women and exercise: explanatory concepts

BACKGROUND

Older women remain predominantly sedentary despite potential health benefits and reduced risks of cardiovascular disease associated with regular exercise. Primary care interventions to increase exercise need to focus on constructs amenable to intervention that predict exercise behavior.

PURPOSE

The study tested an explanatory model of older women's exercise behavior using concepts from social cognitive theory, the transtheoretical model, and the theory of planned behavior (self-efficacy, outcome expectancy, perceived exercise barriers, processes of change, perceived health, and age).

METHODS

Data were collected by interviews with 203 older community-dwelling women physically capable of some exercise. Ordinary least squares regression results were used to determine the direct and indirect effects in a path model.

FINDINGS

All concepts and 13 hypothesized paths were retained in the trimmed model. The constructs accounted for 46% of the variance in exercise behavior. Outcome expectancy had the largest total effect. Processes of change had the largest direct effect on exercise behavior. Exercise self-efficacy and perceived exercise barriers accounted for similar amounts of variance in exercise behavior, whereas age and health had only modest effects.

CONCLUSION

Important constructs for future exercise model testing and intervention research should include outcome expectancy, processes of change, exercise self-efficacy, and perceived barriers to exercise. Primary care interventions designed to increase older women's exercise should focus on these same constructs.

Validation of a stages of exercise change questionnaire

The purpose of this study was to examine evidence for the validity of a stages of change measure of the Transtheoretical Model for exercise behavior. Participants were 152 university students (53.3% women, 71.6% Caucasian, M age = 19.18 years) who completed processes of change, self-efficacy, decisional balance, stages of change, and exercise behavior questionnaires as well as a maximal treadmill test. Participants in the action and maintenance stages had the highest strenuous (PC/C/P < A/M) and moderate (PC/C < A/M) self-reported exercise behavior. Those in the maintenance stage had the highest estimated aerobic fitness (PC/P < MA). The differences between the early stages (PC, C, and P) and the later stages (A and M) as described by the first function were primarily due to the behavioral process of change. The differences between the extreme stages (PC and M) and the middle stages (C, P, and A) were due to the experiential processes of change and the pros of decisional balance. The hypothesized patterns of stage differences were partially supported. Failure to obtain full support may have been due to methodological issues or inherent difficulties in detecting evidence for the validity of stages of change measures.

Construct validity of the stages of change of exercise adoption for different intensities of physical activity in four samples of differing age groups

PURPOSE

To examine whether the stages of change of exercise adoption appropriately address strenuous, moderate, and mild intensities of physical activity.

DESIGN AND SETTING

Secondary analysis of four data sets investigating transtheoretical model (TTM) constructs for exercise adoption.

SUBJECTS

Four samples of differing age groups (adolescents, n = 400; college students, n = 240; adults, n = 346; seniors, n = 504).

MEASURES

Stage of change algorithm for exercise adoption and self-reported physical activity.

RESULTS

Multivariate analysis of variance (MANOVA) results showed that stages of change were distinguished by strenuous and moderate but not mild exercise in the adolescent, college student, and adult sample. In the senior sample, stage differences were found in the frequency of exercising (equivalent for moderate to strenuous exercise) and the frequency of walking (equivalent for mild exercise). Bivariate correlation coefficients as well as sensitivity, specificity, and related quality indices decreased respectively from strenuous to moderate to mild exercise and from exercising to walking.

CONCLUSIONS

Results provide additional support for the construct validity of the stages of change for strenuous and moderate intensities of physical activity. Development of a new stage assessment instrument for mild intensities of physical activity is recommended. Limitations include use of a different validation measure of exercise behavior in the senior sample.

Factors affecting levels of physical activity in adults

A large proportion of adults in Western cultures are physically inactive, despite several decades of warnings about the potentially negative health consequences of a sedentary lifestyle. Efforts to promote physical activity have focused on identifying its determinants and designing interventions that might effectively promote regular physical activity. The multitude of factors that induce adults to initiate and maintain programmes of physical activity have been divided into those that are invariable (age, gender, race, ethnicity) and those that are presumed to be modifiable (behavioural and personality characteristics, environmental circumstances and community settings). The lack of consistency in the design, analysis and reporting of interventions in the lives of inactive or sedentary individuals has produced equivocal results. However, several social and environmental factors have systematically emerged as determinants of physical activity in adults. In ethnic minorities, the removal of barriers such as unaffordable facilities and unavailable childcare, high crime rates, fear for personal safety and culturally inappropriate activities are of primary importance. Social support from family, peers, communities and healthcare providers has resulted in modest improvements across cultures, ages and genders in selected settings, but the definition of specific interventions and their outcomes deserve additional attention. Longitudinal studies indicate that components of physical fitness are relatively transitory, with low to modest correlations between physical activity and measures of physical fitness in childhood and adolescence and in adulthood. Attempts to explain the activity behaviour of adults by applying various theories in programmes of intervention have also produced mixed results. Successful interventions tailor programmes to individual needs, account for personal levels of fitness, allow for personal control of the activity and its outcomes, and provide for social support by family, peers and communities. The initiation and maintenance of regular physical activity in adults depends on a multitude of biological and sociocultural variables that demand attention across the lifespan.