Barriers and facilitators to exercise adherence in community-dwelling older adults: A mixed-methods systematic review using the COM-B model and Theoretical Domains Framework

BACKGROUND

Although the health benefits of exercise for older adults are widely recognized, physical inactivity is still common among older adults. Further clarification of the factors affecting exercise adherence is needed to develop more effective exercise interventions in community-dwelling older adults.

OBJECTIVE

The purposes of this study were to identify (1) barriers and facilitators of exercise adherence in community-dwelling older adults and (2) behavior change techniques (BCTs) and implementation strategies that are potentially effective in improving adherence.

METHODS

A total of eight databases were searched: PubMed, Web of Science, EMBASE, CENTRAL, PsycINFO, SPORTDiscus, MEDLINE, and Scopus. Studies published from database inception to April 2023 were searched. The quality of the included studies was assessed using the Mixed Methods Appraisal Tool (MMAT). The Capabilities, Opportunities, Motivations, Behavior (COM-B) model and the Theoretical Domain Framework (TDF) were used to identify potential barriers and facilitators. The BCTs were used to identify potential intervention implementation strategies.

RESULTS

A total of 64 studies were included, including 30 qualitative studies, 12 randomized controlled trials, 12 mixed methods studies, 6 quantitative descriptive studies, and 5 non-randomized trials. 54 factors influencing adherence and 38 potentially effective BCTs were identified from the included studies. The 38 BCTs were further categorized into 8 areas of implementation strategies (tailored exercise program, appropriate exercise environment, multidimensional social support, monitoring and feedback, managing emotional experiences and issues, participants education, enhancing self-efficacy, and exerting participants' autonomy).

CONCLUSION

This study identified 54 influential factors affecting exercise adherence and identified 8 areas of intervention strategies (containing 38 BCTs). Further refinement, evaluation, and validation of these factors and strategies are needed in future studies.

Association between participation in social network service groups and offline social networks

AIM

Although some previous studies have suggested using a social networking service (SNS) to create and maintain offline social networks among younger generations, whether similar outcomes would apply to middle-aged and older individuals is uncertain. This study aimed to examine the association between participation in groups via SNS and greater offline social networks among middle-aged and older individuals.

METHODS

We conducted a web-based questionnaire survey on 3106 respondents from September to October 2021 among members of "the Shumi-to Club," an SNS in Japan. They indicated the number of SNS groups they belonged to and were classified into two categories, namely, those with and without participation in SNS groups. The current study assessed offline social networks using the total frequency of face-to-face interactions with distant family members and friends. Ordinal logistic regression analyses were performed, and the frequency of offline interactions was set as the outcome with adjustment for sociodemographic variables and self-rated health.

RESULTS

Approximately 70.8% (n = 2200) of the participants belonged to SNS groups. Participation in SNS groups was associated with higher frequencies of face-to-face interaction with friends (odds ratio [95% confidential intervals]: 1.78 [1.53-2.07]). However, the current study found no association between belonging to a group and face-to-face interaction with distant family members (1.09 [0.93-1.26]).

CONCLUSIONS

The participation in SNS groups potentially promotes offline social networks, particularly with friends. Geriatr Gerontol Int 2024; 24: 279-284.

Racial and ethnic differences in predictors of participation in an intergenerational social connectedness intervention for older adults

BACKGROUND

Social connectedness is a key determinant of health and interventions have been developed to prevent social isolation in older adults. However, these interventions have historically had a low participation rate amongst minority populations. Given the sustained isolation caused by the COVID-19 pandemic, it is even more important to understand what factors are associated with an individual's decision to participate in a social intervention. To achieve this, we used machine learning techniques to model the racial and ethnic differences in participation in social connectedness interventions.

METHODS

Data were obtained from a social connectedness intervention that paired college students with Houston-area community-dwelling older adults (> 65 yo) enrolled in Medicare Advantage plans. Eligible participants were contacted telephonically and asked to complete the 3-item UCLA Loneliness Scale. We used the following machine-learning methods to identify significant predictors of participation in the program: k-nearest neighbors, logistic regression, decision tree, gradient-boosted decision tree, and random forest.

RESULTS

The gradient-boosted decision tree models yielded the best parameters for all race/ethnicity groups (96.1% test accuracy, 0.739 AUROC). Among non-Hispanic White older adults, key features of the predictive model included Functional Comorbidity Index (FCI) score, Medicare prescription risk score, Medicare risk score, and depression and anxiety indicators within the FCI. Among non-Hispanic Black older adults, key features included disability, Medicare prescription risk score, FCI and Medicare risk scores. Among Hispanic older adults, key features included depression, FCI and Medicare risk scores.

CONCLUSIONS

These findings offer a substantial opportunity for the design of interventions that maximize engagement among minority groups at greater risk for adverse health outcomes.

"It doesn't feel like exercise": a realist process evaluation of factors that support long-term attendance at dance classes designed for healthy ageing

Introduction

Dance can positively impact older people's health and wellbeing across cultures and socioeconomic groups, countering age-related physical, sensorimotor and cognitive decline.

Background/objectives

The RIPE (Really Is Possible for Everyone) Dance program aims to improve older people's physical, mental, cognitive and social wellbeing by integrating engaging dance sequences with evidence-based fall prevention exercises. We sought to identify what mechanisms support observed long-term participation in this program, including by people living with challenging health conditions.

Methods

Following a realist evaluation approach, we co-developed and tested program theories iteratively with participant interviewees (n = 20), dance teachers (n = 2) and via observation of a dance class. Initial data were dual-coded and emergent findings were interrogated by the research team. Findings were organised to express Program activities + Context + Mechanism = Process outcomes configurations.

Results

We identified four program theories comprising 14 mechanisms which explained long-term attendance: 1. RIPE Dance benefits my body and mind (trust in the program, belief in health benefits), 2. RIPE Dance helps me feel good about myself (self-efficacy, pride in achievement, psychological safety, defying expectations, feeling valued), 3. RIPE Dance creates camaraderie (social connection, mutual support, rapport with the teacher), and 4. RIPE Dance is uplifting (raised spirits, fun, synchrony, musical reactivity).

Conclusion

The RIPE Dance program provides effective and enjoyable 'exercise in disguise' for older people with diverse mobility profiles.

Significance/implications

This research confirms that participation in dance can contribute significantly to healthy, happy ageing. Findings detail program activities that were most strongly associated with process outcomes, offering guidance for further program development, implementation and scaling up.

Older Mens' Experiences with and Preferences for Physical Activity

We aim to describe older mens' experiences with physical activity (PA) and their preferences for PA programs. We interviewed 14 men from a Canada-based PA intervention study called Men on the Move, and 5 men from a supplementary sample (who were not intervention participants). Content analysis was used to describe their experiences with PA and program preferences. The socio-ecological perspective and the hegemonic masculinity framework guided the research. PA barriers were low motivation, poor health, lack of time, interests other than PA and a lack of interest in PA, finances, lack of knowledge about PA, injury fear, social influences, inconvenience, weather, caregiving, built/natural environments, low-quality fitness instructors, and program structure. PA facilitators were chores, health, interest, time, motivation, social influences, active transportation, built/natural environments, good weather, program structure, and skilled/knowledgeable fitness instructors. PA program preferences were small group atmosphere, individualized attention/programming, equal number of men and women, sports programming, PA classes, and experienced instructors. Older men have distinct PA experiences. Promoting and designing programs that address their experiences may increase their PA.

Barriers and enablers associated with participation in a home-based pragmatic exercise snacking program in older adults delivered and monitored by Amazon Alexa: a qualitative study

BACKGROUND

'Exercise snacking', which is characterised by shorter and more frequent exercise bouts compared with traditional exercise guidelines, may be an acceptable strategy for increasing physical activity and reducing sedentary behaviour in older adults.

AIM

The aim of this study was to evaluate the enablers and barriers for older adults associated with participation in a home-based exercise snacking program delivered and monitored using an Amazon Echo Show 5 device (Alexa).

METHODS

This study used an interpretive description qualitative design to conduct semi-structured interviews following a 12-week pilot study in 15 adults aged 60-89 years with at least one chronic condition. All participants were prescribed a home based, individualised, lower limb focussed 'exercise snacking' program (involving ≤ 10 min of bodyweight exercises 2-4 times per day) delivered and monitored by an Alexa. Qualitative interview data were analysed using thematic analysis.

RESULTS

All 15 participants (mean age 70.3 years) attended the semi-structured interview. Themes including time efficiency, flexibility, perceived health benefits, and motivation were enablers for participation in the 'exercise snacking' program. A lack of upper body exercises and omission of exercise equipment in the program, as well as a lack of time and motivation for performing exercise snacks three or more times per day, were barriers to participation.

CONCLUSION

While 'exercise snacking' is acceptable for older adults, future trials should provide equipment (e.g. adjustable dumbbells, exercise bands), prescribe whole-body exercise programs, and establish strategies to support participation in more than three exercise snacks per day.

Potential Benefits of Physical Activity in MCI and Dementia

Physical activity improves overall health and reduces the risk of many negative health outcomes and may be effective in improving cognition, independent functioning, and psychological health in older adults. Given the evidence linking physical activity with improvements in various aspects of health and functioning, interventions exploring pathways for decreasing risk of dementia in those with mild cognitive impairment (MCI) and improving outcomes for those with dementia are of critical importance. The present review highlights the work examining physical activity interventions in order to achieve a comprehensive understanding of the potential benefits of physical activity for individuals experiencing cognitive decline. The primary focus is on aerobic exercise as this is the main intervention in the literature. Our review supports the thesis that physical activity can promote healthy aging in terms of cognition, independent functioning, and psychological health for individuals experiencing cognitive decline. Specifically, physical activity improves cognition, especially executive functioning and memory in MCI, independent functioning in MCI and dementia, and psychological health in dementia. Given that benefits of physical activity have been observed across these domains, such interventions provide an avenue for preventing decline and/or mitigating impairment across several domains of functioning in older adults with MCI or dementia and may be recommended (and adjusted) for patients across a range of settings, including medical and mental health settings. Further implications for clinical intervention and future directions for research are discussed.

Promoting Exercise Adherence Through Groups: A Self-Categorization Theory Perspective

The hypothesis presented in this paper is that adherence to exercise programs can be understood, and fostered through intervention, by considering how social identities form within group settings. This paper explains these processes from a self-categorization theory perspective.

Beginning With the End in Mind: Contextual Considerations for Scaling-Out a Community-Based Intervention

Introduction: A number of effective physical activity programs for older adults exist, but are not widely delivered within community settings, such as the Cooperative Extension System. The purpose of this paper was to determine if an evidence-based intervention (EBI) developed in one state Extension system could be scaled-out to a new state system. Methods and results: The RE-AIM (reach, effectiveness, adoption, implementation, maintenance) framework was used to guide an iterative evaluation of three translational stages. Stage 1: Before program adoption, Extension health educators were surveyed and interviewed to assess physical activity programming perceptions and factors that may influence their decision to attend training or deliver the program in practice. Results indicated that a virtual, scalable training protocol would be necessary and that training needed to include hands-on instruction and be catered to those who were less confident in physical activity program delivery. Stage 2: Training attendees were surveyed pre- and post-training on factors related to the adoption-decision making process and contacted post-training to assess program delivery status. Training did not influence perceptions of the program, intent to deliver, or confidence in delivering the program. Stage 3: During program implementation, the program was evaluated through the RE-AIM framework by surveying across three key stakeholder groups: (1) program participants, (2) potential delivery personnel, and (3) Extension administrators. Findings indicate that the program has the potential to reach a large and representative proportion of the target audience, especially in rural areas. However, adoption and implementation rates among Extension health educators and community partners were low and data collection for effectiveness, implementation, and maintenance was a challenge. Conclusion: Overall, the results indicate initial struggles to translating and evaluating the program in a large, rural state. Implications for practice include making system-level changes to increase physical activity program adoption rates among Extension health educators and improve data collection and program evaluation through this community-based organization. More work is needed to identify infrastructure support and capacity to scale-out EBIs.

Coping Strategies, Psychological Impact, and Support Preferences of Men With Rheumatoid Arthritis: A Multicenter Survey

Objective

To investigate the existence and distribution of 2 typologies (termed “factors”) of men with rheumatoid arthritis (RA) identified through our previous Q‐methodology study (n = 30) in a larger sample of men with RA, and whether differences in psychosocial impact or support preferences exist between the 2 factors, and between men and women with RA.

Methods

A postal survey was sent to 620 men with RA from 6 rheumatology units across England, and the support preferences section of the survey was given to 232 women with RA.

Results

A total of 295 male patients (47.6%) and 103 female patients (44.4%) responded; 15 male participants had missing data, and thus 280 were included in the analysis. Of these, 61 (22%) were assigned to factor A (“accept and adapt”), 120 (35%) were assigned to factor B (“struggling to match up”), and 99 (35%) were unassigned. The two factors differed significantly, with factor B reporting more severe disease, less effective coping strategies, and poorer psychological status. For support, men favored a question and answer session with a consultant (54%) or specialist nurse (50%), a website for information (69%), a talk by researchers (54%), or a symptom management session (54%). Overall, women reported more interest in support sessions than men, with ≥50% of women reporting interest in nearly every option provided.

Conclusion

Some men accept and adapt to their RA, but others (43%) report severe disease, less effective coping, and poor psychological status. Men's preferences for support are practical, with a focus on expanding their knowledge.

Barriers and enablers to ongoing exercise for people with chronic health conditions: Participants' perspectives following a randomized controlled trial of two interventions

BACKGROUND

At present there is no clear evidence to support any one particular intervention for engaging adults with chronic health issues in ongoing exercise. An understanding of consumer perceptions and preferences is important, because low rates of exercise adherence are likely to limit any benefits obtained.

OBJECTIVE

To identify and compare participants' perceptions about their own motivation, capacity and opportunity to adhere to an allocated exercise program during either a gym-based or a home-based exercise program with telephone follow-up.

METHOD/DESIGN

This qualitative study used convenience sampling to recruit participants (adults with chronic health issues) immediately after a randomised controlled trial comparing gym-and home-based exercise programs conducted for 12 months. Ten people, five from each intervention group, attended face-to- face semi-structured interviews at a local Community Health Service. Thematic analysis methods were used to analyse the dataset.

RESULTS

Improved social interaction in the gym-based program was seen to contribute to adherence, however home-based programs were perceived as more convenient and easily integrated into daily routines. Individualized exercise prescription by a health professional with regular follow up (in person or by telephone) promoted an active practitioner-participant relationship. Health coaching combined with exercise was perceived to improve self-efficacy and assisted with the removal of intrinsic and extrinsic exercise barriers.

CONCLUSION

This research presented many common and different themes in participant's motivation, capacity and opportunity in sustained adherence to a gym or home-based exercise program. However, this study found no superior intervention or individual preference to improve ongoing exercise adherence.

Development of a physical literacy model for older adults - a consensus process by the collaborative working group on physical literacy for older Canadians

BACKGROUND

Arguably the uptake and usability of the physical activity (PA) guidelines for older adults has not been effective with only 12% of this population meeting the minimum guidelines to maintain health. Health promoters must consider innovative ways to increase PA adoption and long-term sustainability. Physical literacy (PL) is emerging as a promising strategy to increase lifelong PA participation in younger age-groups, yet there is relatively little evidence of PL being used to support older adults in achieving the PA guidelines.

METHODS

An iterative and mixed-methods consensus development process was utilized over a series of six informed processes and meetings to develop a model of physical literacy for adults aged 65 years and older.

RESULTS

A multi-disciplinary collaborative working group (n = 9) from diverse practice settings across Canada, and representative and reflective of the full range of key elements of PL, was assembled. Three consensus meetings and two Delphi surveys, using an international cohort of 65 expert researchers, practitioners, non-government organizations and older adults, was conducted. 45% responded on the first round and consensus was achieved; however, we elected to run a second survey to support our results. With 79% response rate, there was consensus to support the new PL model for older adults.

CONCLUSION

Older adults are a unique group who have yet to be exposed to PL as a means to promote long-term PA participation. This new PL model uses an ecological approach to integrate PL into the lifestyles of most older adults. Understanding the interactions between components and elements that facilitate PL will ultimately provide a new and effective tool to target PA promotion and adherence for all older Canadians.

Facilitators of Attendance and Adherence to Group-Based Physical Activity for Older Adults: A Literature Synthesis

This review examines program features that influence attendance and adherence to group-based physical activity (PA) by older adults. Medline, PubMed, CINAHL plus, PsycINFO, and the Cochrane Library were searched for studies published from 1995-2016. Quantitative and qualitative studies investigating factors related to PA group attendance or adherence by persons aged 55 years and over were included. Searching yielded eight quantitative and 13 qualitative studies, from 2,044 titles. Quantitative findings identified social factors, instructor characteristics, PA types, class duration and frequency, and perceived PA outcomes as important for attendance and adherence, whilst qualitative studies identified settings, leadership, PA types, observable benefits, and social support factors. Studies were predominantly low- to moderate-quality. This review identified design and delivery considerations for group-based PA programs to inform best-practice frameworks and industry capacity building. Future research should use longitudinal and mixed-methods designs to strengthen evidence about facilitators of program reach and engagement.

Older people's adherence to community-based group exercise programmes: a multiple-case study

BACKGROUND

Physical inactivity is a global phenomenon, with estimates of one in four adults not being active enough to achieve health benefits, thus heightening the risk of developing non-communicable diseases. In order to realise the health and wellbeing gains associated with physical activity the behaviour must be sustained. Community-based group exercise programmes (CBGEP) utilising social supports have been shown to be one means of not only increasing activity levels for older people, but sustaining physical activity. A gap in the literature was identified around older people's long-term adherence to real-life CBGEP within a UK context. This study therefore sought to address this gap by understanding older people's ongoing adherence to CBGEP with a view to gaining further insight about which factors contribute to enabling people to sustain their physical activity levels.

METHODS

A multiple case study research design was employed to understand older people's (≥60 years, n = 27) adherence (≥ 69%, for ≥ 1 year) to three current CBGEP in the South- West of England. Qualitative data (participant observation, focus groups, documents, and interviews) were collected and analysed using inductive thematic analysis followed by the analytic technique of explanation building. Quantitative data were analysed using descriptive statistics and used to set the context of the study.

RESULTS

The current study offers five unique insights into real-life programmes which have been successful in helping older people maintain adherence for a year or longer. These included: factors relating to the individual, the instructor (particularly their personality, professionalism and humanised approach), programme design (including location, affordability, the use of music, and adaptable exercise content), social features which supported a sense of belonging, and participant perceived benefits (physical and psycho-social). These all served to explain older people's adherence to CBGEP.

CONCLUSIONS

These factors related to participant adherence of CBGEP must be considered if we wish to support older people in sustaining a physically active lifestyle as they age. These findings are of interest to practitioners and policy makers in how CBGEP serve to aid older people in maintaining a physically active lifestyle with a view to preventing non-communicable diseases and in maintaining social connectivity.

A group-enhanced sprint interval training program for amateur athletes

Sprint interval training (SIT) can elicit improvements in aerobic and anaerobic capacity. While variations in SIT protocols have been investigated, the influence of social processes cannot be overlooked. As research supports the use of groups to influence individual cognitions and behaviours, the current project assessed the effectiveness of a group-based intervention with participants conducting SIT. Specifically, 53 amateur athletes (age, 21.9 ± 2.9 years; 53% females) took part in a 4-week training program (3 sessions per week, 30-s “all-out” efforts with 4 min active recovery, repeated 4–6 times per session), and were assigned to “true group”, aggregate, or individual conditions. Results indicated no significant differences between groups for the physiological measures. With regards to training improvements from baseline for all participants— regardless of condition — significant main effects for time were identified for maximal oxygen uptake (2.5–2.8 mL·kg−1·min−1, p < 0.001, η2 = 0.03), time-trial performance (14–32 s, p < 0.001, η2 = 0.37), and anaerobic power (1.1–1.7 k·h−1, p < 0.001, η2 = 0.66). With regards to the psychological measures, significant main effects between groups were found for motivation (p = 0.033, η2 = 0.13), task self-efficacy (p = 0.018, η2 = 0.15), and scheduling self-efficacy (p = 0.003, η2 = 0.22). The true group experienced greater improvements in motivation than the individual condition, but the aggregate and individual conditions demonstrated greater increases in task and scheduling self-efficacy. Though the SIT paradigm employed induced training improvements similar to previous work, the group intervention was not able to further these improvements.

Adherence to community based group exercise interventions for older people: A mixed-methods systematic review

OBJECTIVE

Lifelong physical activity provides some of the best prospects for ageing well. Nevertheless, people tend to become less physically active as they age. This systematic review assessed the views and adherence of participants attending community based exercise programmes of ≥6month's duration.

METHOD

Searches were carried out in eight online scientific databases (January 1995-May 2014) to identify relevant primary studies. Studies were assessed for quality and data extracted. Results were synthesised thematically and narratively. Qualitative findings were compared against quantitative studies.

RESULTS

A total of 2958 studies were identified and screened against the inclusion/exclusion criteria. Ten studies met the inclusion criteria (five quantitative, three qualitative and two mixed-methods study designs). None were excluded on the basis of quality. Six key themes were identified from the qualitative studies as important for adherence to group exercise programmes: social connectedness, participant perceived benefits, programme design, empowering/energising effects, instructor and individual behaviour. The mean adherence rate of studies with comparable measures was (69.1% SD 14.6). When the views of participants from the qualitative synthesis were juxtaposed against the quantitative studies, programme design was a common feature across all studies.

CONCLUSION

Evidence surrounding these programmes is limited both in terms of long-term adherence measures and the views of participants. However, based on limited findings there is some indication that community based group exercise programmes have long-term adherence rates of almost 70%. Incorporating the views of older people into programme designs may provide guidance for innovative interventions leading to sustained adherence.

GrOup based physical Activity for oLder adults (GOAL) randomized controlled trial: study protocol

BACKGROUND

Physical activity has health benefits across the lifespan, yet only 13 % of Canadian older adults are sufficiently active. Results from a number of observational studies indicate that adults display positive preferences for exercising with others of a similar age and same gender, and that intra-group age- and gender-similarity are associated with elevated exercise adherence. However, research has yet to experimentally examine the extent to which intra-group age- and gender-related similarity affect exercise adherence behaviors.

METHODS/DESIGN

The GrOup-based physical Activity for oLder adults (GOAL) trial is a three-arm randomized control trial that will examine the efficacy of two different group-based exercise programs for older adults (informed by the tenets of self-categorization theory) in relation to a standard group-based exercise program. Within this manuscript we outline the design and proposed evaluation of the GOAL trial. The first arm is comprised of exercise groups made up of participants of a similar-age and of the same gender; the second arm consists of groups with similar-aged mixed gender participants; the control arm is comprised of mixed-aged mixed gender participants. We aim to compare the adherence rates of participants across conditions, as well as potential moderation effects and mediating mechanisms.

DISCUSSION

Results from this trial will inform intervention designs to improve the exercise adherence behaviors of older adult. At a systems-level, should support be derived for the efficacy of the interventions tested in this trial, changing group composition (i.e., age, gender) represents a feasible program adaptation for physical activity centers.

TRIAL REGISTRATION

ClinicalTrials.gov # NCT02023632 . Registered December 13, 2013.

Engineering online and in-person social networks to sustain physical activity: application of a conceptual model

BACKGROUND

High rates of physical inactivity compromise the health status of populations globally. Social networks have been shown to influence physical activity (PA), but little is known about how best to engineer social networks to sustain PA. To improve procedures for building networks that shape PA as a normative behavior, there is a need for more specific hypotheses about how social variables influence PA. There is also a need to integrate concepts from network science with ecological concepts that often guide the design of in-person and electronically-mediated interventions. Therefore, this paper: (1) proposes a conceptual model that integrates principles from network science and ecology across in-person and electronically-mediated intervention modes; and (2) illustrates the application of this model to the design and evaluation of a social network intervention for PA.

METHODS/DESIGN

A conceptual model for engineering social networks was developed based on a scoping literature review of modifiable social influences on PA. The model guided the design of a cluster randomized controlled trial in which 308 sedentary adults were randomly assigned to three groups: WalkLink+: prompted and provided feedback on participants' online and in-person social-network interactions to expand networks for PA, plus provided evidence-based online walking program and weekly walking tips; WalkLink: evidence-based online walking program and weekly tips only; Minimal Treatment Control: weekly tips only. The effects of these treatment conditions were assessed at baseline, post-program, and 6-month follow-up. The primary outcome was accelerometer-measured PA. Secondary outcomes included objectively-measured aerobic fitness, body mass index, waist circumference, blood pressure, and neighborhood walkability; and self-reported measures of the physical environment, social network environment, and social network interactions. The differential effects of the three treatment conditions on primary and secondary outcomes will be analyzed using general linear modeling (GLM), or generalized linear modeling if the assumptions for GLM cannot be met.

DISCUSSION

Results will contribute to greater understanding of how to conceptualize and implement social networks to support long-term PA. Establishing social networks for PA across multiple life settings could contribute to cultural norms that sustain active living.

TRIAL REGISTRATION

ClinicalTrials.gov NCT01142804.