- Open Access
Evaluating the reach, effectiveness, adoption, implementation and maintenance of the Resistance Training for Teens program
International Journal of Behavioral Nutrition and Physical Activity volume 18, Article number: 122 (2021)
Physical activity guidelines recommend young people engage in regular muscle-strengthening activities (e.g., resistance training [RT]). However, few school-based physical activity interventions have been delivered at-scale or promoted RT. The aim of this study was to evaluate the reach, effectiveness, adoption, implementation and maintenance of the Resistance Training for Teens (RT for Teens) program.
Data were collected between August 2015 and October 2020. RE-AIM was operationalized as: (i) Reach: number and characteristics of students estimated to be exposed to the program; (ii) Effectiveness: impact of the program on student-level outcomes measured in a subsample of 750 students from 17 schools; (iii) Adoption: number and representativeness of schools with one or more teachers trained to deliver the program; (iv) Implementation: extent to which the program was delivered as intended; and (v) Maintenance: extent to which the program was sustained in schools.
The estimated program reach was ~ 10,000 students, out of a total student population of ~ 200,000 (~ 5%). Students were from diverse socioeconomic and ethnic backgrounds. Improvements in muscular fitness, RT self-efficacy, perceived cardiorespiratory fitness and flexibility, and participation in muscle-strengthening physical activities were documented. A total of 30 workshops were delivered, involving 468 teachers from 249 schools from diverse geographical regions. Implementation varied considerably, with teachers adapting the program to suit the context of their school and student cohorts. However, RT skill development and the promotion of muscular fitness were the session components delivered most during sessions. Teachers’ adherence to the SAAFE (Supportive, Active, Autonomous, Fair and Enjoyable) teaching principles was high. Approximately 30% of teachers (144/476) registered to use the RT for Teens app. At the school-level, 37% (93/249) of schools had at least one registered user (teacher and/or student). A total of 2,336 workouts and 3,116 fitness tests were completed by registered users. Of the 249 schools represented, 51 (20.5%) sent an additional (previously untrained) teacher to a second workshop.
The RT for Teens program had broad reach and adoption. However, intervention delivery varied considerably across schools and additional support strategies are required to optimize intervention implementation and maintain program delivery over time. Future studies will benefit from the utilization of accepted frameworks, recommendations and guidelines for implementation research.
Australian New Zealand Clinical Trials Registry (ACTRN12621000352808), retrospectively registered 1st February 2021.
The health benefits of muscular fitness for adults  and youth  are compelling. As a result, international guidelines recommend young people (5–17 years) engage in muscle-strengthening activities (e.g., resistance training [RT]) on at least three days per week . Despite this recommendation, 51% of United States (US) high school students , and only 13% of Australians aged 15–17  are meeting this guideline. Adult data from the US , Europe , and Australia  suggest slightly lower participation, with 21.9%, 17.3% and 9.3% meeting muscle-strengthening activity guidelines (i.e., ≥ 2 days/week), respectively [9,10,11]. A number of barriers to participation in RT exist amongst adults, including low self-efficacy, negative affective judgement (i.e., negative feelings about RT) and lack of self-regulation strategies (e.g., goal setting and self-monitoring for RT) . These barriers are also relevant for adolescents, as they may lack the knowledge, skills and/or confidence to participate, despite their desire to try varied physical activities . In addition to individual-level barriers, parental attitudes towards RT  may influence adolescents’ participation opportunities in RT. Providing adolescents with opportunities to develop the necessary skills, knowledge, and self-efficacy  to engage in RT may help to overcome these barriers  and support lifelong participation.
Secondary schools are well-positioned to introduce young people to RT as they have the access and curriculum to target health behaviors. They are also uniquely placed with personnel, such as physical education (PE) teachers, who may have the expertise to deliver RT programs. Unfortunately, there are notable barriers to the delivery of RT in schools, including lack of appropriate facilities, equipment, teacher confidence, and time [16, 17]. Additionally, teachers may be uncertain of how to integrate RT into school programs, and may subscribe to misconceptions related to the appropriateness of RT for youth (i.e., safety, injury risks and potential to stunt growth) . These issues may explain why few school-based physical activity interventions have focused on the promotion of RT . Among those that have, most have been time intensive  and focused on the use of specialized weight training equipment . Whilst these interventions may have improved both physical [20, 21] and psychological  outcomes on a small scale, there is a need to test school-based RT interventions that are scalable.
The need for widespread rollout of successful physical activity interventions has been well documented [22,23,24,25]. However, few school-based physical activity interventions have progressed beyond pilot, efficacy or effectiveness phases to be delivered at-scale [22, 26]. Developing effective interventions is only the first step toward improving population health. Transferring and sustaining effective programs into real world settings (such as schools) is a complicated and long-term process . Scaling-up is the term used to describe the process of expanding the reach of efficacious health interventions under real-world conditions into broader policy or practice . The Reach, Effectiveness, Adoption, Implementation and Maintenance (RE-AIM) framework  has been used extensively to evaluate the scale-up of effective health promotion interventions. RE-AIM allows for the assessment of both internal and external validity, which can help determine the public health impact of an intervention .
The Nutrition and Enjoyable Activity for Teen (NEAT) Girls  and Active Teen Leaders Avoiding Screen-time (ATLAS)  were two gender-targeted school-based interventions for girls and boys, respectively. They were designed to prevent obesity and promote physical activity among secondary school students in New South Wales (NSW), Australia. Positive findings from these programs included improvements in body composition , muscular fitness , and RT skill competency , as well as reduced recreational screen time [32, 33]. Despite their effectiveness, both programs included a large number of intervention components and required high levels of support from the research team, limiting their scalability . Following the completion of the NEAT and ATLAS trials, the programs were adapted using feedback from participants , as well as our key stakeholder (i.e., the NSW Department of Education [DoE]). The goal of this process was to optimize  the intervention, through reviewing the existing intervention features, and identifying essential and non-essential components. This resulted in the new, consolidated, ‘Resistance Training for Teens’ (RT for Teens) program.
The multi-component RT for Teens intervention was designed to improve muscular fitness and provide adolescents with the knowledge, motivation, skills, and confidence to engage in RT. The scalability of the intervention was optimized  through the inclusion of the following features: i) partnership with the NSW DoE; ii) flexibility of delivery within PE, school sport, or a PE-based elective subject (known as Physical Activity and Sport Studies); iii) reduction of program duration to fit within one school term (i.e., 10-weeks); iv) teacher-led delivery of the program, including training and resource provision; iv) smartphone application (app) to support program delivery; and v) greater focus on bodyweight exercises without the need for equipment or access to a gym.
RT for Teens was initially evaluated via a cluster randomized controlled trial (RCT) . At the primary endpoint of 6-months, we observed significant improvements in adolescents’ muscular fitness, RT skill competency, and RT self-efficacy . Improvements in muscular fitness and RT skill competency were also maintained at long-term follow-up (i.e., 12-months) . Notably, students who were classified as overweight/obese had greater improvements in outcomes including upper body muscular fitness, RT skill competency, and motivation for RT . The RT for Teens program followed a comprehensive pathway to scale-up, flowing through all four stages described by Indig and colleagues . These four stages included: i) theory driven program development (i.e., guidance by Social Cognitive Theory and Self-Determination Theory); ii) testing for efficacy (i.e., original NEAT Girls  and ATLAS  programs); iii) testing for replicability/effectiveness (RT for Teens cluster RCT [36, 38]); and iv) the RT for Teens dissemination trial (i.e., the present study). Program development and rationale [39,40,41], and findings from the efficacy [32, 33] and effectiveness/replicability stages [36, 38] have been published previously. The aim of the current study was to evaluate the reach, effectiveness, adoption, implementation and maintenance of the RT for Teens program.
A type 2 hybrid effectiveness-implementation trial design  was used to assess both intervention outcomes and implementation strategies. Student- (reach, effectiveness), teacher- (adoption, implementation) and school-level (adoption, implementation, maintenance) data were examined . The operationalisation of RE-AIM dimensions, RE-AIM data sources, outcome descriptions, and analytical methods are presented in Table 1. The RE-AIM framework  was chosen as the tool for evaluating the RT for Teens study as it balances internal and external validity, with the versatility to be used across all stages of research (from pilot to dissemination). Additionally, RE-AIM includes dimensions related to both outcome assessment and implementation quality , which are essential components when conducting a type 2 hybrid effectiveness-implementation trial . Mixed methods were utilized, to maximize available data for the evaluation . Ethics approval was obtained from the human research ethics committees of the University of Newcastle, Australia (H-2014–0312) and NSW DoE (SERAP: 2012121). Written informed consent was obtained from all school Principals and teachers. Study participants and their parents/caregivers were provided with information statements and opt-out consent was applied. The design and methods have been reported in detail previously . RT for Teens was evaluated in two phases. The first phase (i.e., cluster RCT) took place in mid-2015 (ACTRN126150003605167). The second phase, (i.e., state-wide dissemination) commenced in late 2015 and was retrospectively registered (ACTRN12621000352808).
All government and non-government secondary schools in NSW were eligible to participate in the dissemination phase. Dissemination has an inherent goal of adoption , whereby strategies are used to promote an intervention to the target population [54, 55]. Dissemination strategies were aimed at secondary school teachers as these were the initial target audience for the RT for Teens program. One strategy was the training of teachers to deliver the program, during a professional learning workshop delivered by the research team. This workshop was an accredited one-day training opportunity (i.e., teachers gained 5-h towards industry-mandated annual professional learning requirements), for teachers of any specialization. The workshop included practical and theoretical components designed to provide teachers with the knowledge, skills and competence to deliver the RT for Teens program. The workshop was adapted from the original RCT workshop to include the following content: (1) Program rationale including importance of muscular fitness, secular trends and RT guidelines, (2) Findings from the RT for Teens RCT, (3) Introduction to the RT for Teens program components, and (4) Motivating students using the SAAFE teaching principles. The final section did not highlight the physical limitations of specific groups (e.g., students with overweight or obesity). Instead it focused on delivering the RT for Teens program using autonomy supportive teaching practices. For example, students could choose to do push-ups on their knees or toes depending upon their perceived level of muscular fitness. Similarly, students were discouraged from comparing themselves to their peers, with the focus on self-improvement rather than competition. Teacher professional learning workshops (N = 30) were delivered from August 2015 until December 2019, with final data for the evaluation collected in October 2020. As an adjunct to the training, and to support program delivery, teachers were also provided with resources, including circuit cards (Fig. 1), access to a purpose-built smartphone app (Fig. 2 and Supplementary Fig. 2), and electronic copies of all workshop content.
Although teachers were the target audience of the workshop, it is important to note that teachers in NSW schools require approval from their head of department and school executive (i.e., principal or deputy principal) to attend professional learning workshops. As such, the decision to ‘adopt’ the RT for Teens program required support from the teachers, their head of department and the school executive. However, we acknowledge that teachers’ attendance at a professional learning workshop does not guarantee that they will successfully implement a program upon returning to school. Regarding implementation, schools were given considerable flexibility in how and when the program could be delivered. For example, it could be delivered as a school sport option, which did not require approval from the head of department. Alternatively, the program could be embedded within PDHPE curricula, which required head of department approval. Finally, we considered the sending of additional teachers to an RT for Teens workshop as an appropriate measure of maintenance because this demonstrates that schools were engaged with the program and wanted to “upskill” additional staff members. Similar to adoption, the decision to send additional teachers to another RT for Teens workshop required support from the teachers themselves, their head of department and the school executive.
Based on the attendance of 468 classroom teachers at the RT for Teens professional learning workshop from 2015–2019, we conservatively estimate that the program reached ~ 10,000 students. This estimate is based on the assumption that teachers who attended training delivered the program to at least one class of 23 students (representing the average class size in NSW government secondary schools) . Characteristics of students enrolled at schools with at least one trained teacher (dissemination cohort) are presented in Table 2. Just over half of students were male, with almost 30% from a language background other than English. Ten percent of students were of Indigenous heritage, and close to 40% from low socio-economic backgrounds. For comparison, characteristics of students enrolled at schools within the ‘effectiveness’ sub-sample are also presented in Table 2. Student characteristics were like that of the entire RT for Teens dissemination cohort, except schools within the effectiveness sub-sample had slightly larger enrollment numbers (~ 150 more students). Data available from NSW DoE specifies that 49% of school students are female . This proportion is comparable to the percentage of females within RT for Teens dissemination cohort, effectiveness sub-sample school cohort, and effectiveness sub-sample student cohort (all ~ 48%). NSW data specifies that 6% of students identify as Aboriginal or Torres Strait Islander . Data from the three RT for Teens groups indicates a slightly higher mean percentage of Indigenous students across these cohorts. Across the dissemination, effectiveness sub-sample school, and effectiveness sub-sample student cohorts, 10%, 8% and 7% reported Indigenous heritage, respectively.
A total of 750 students from 17 schools located in a major city and inner regional areas provided effectiveness data. The characteristics of students in this sub-sample are presented in Table 3. Detailed findings for student-level outcomes are presented in Table 4. From this sample, statistically significant improvements from pre- (week 1) to post-program (week 10) were found for perceived cardiorespiratory fitness (CRF) (0.13 units, 95% CI: 0.07 to 0.19]), perceived flexibility (0.13 units, 95% CI: 0.05 to 0.21), participation in muscle-strengthening physical activities (0.70 days/week, 95% CI: 0.47 to 0.93), and RT self-efficacy (0.09 units, 95% CI: 0.03 to 0.14). In addition to questionnaire data, fitness measures were completed by 11 of the 17 schools. Statistically significant changes from pre- to post-program were found for push-ups (3.2 repetitions, 95% CI: 1.8 to 4.6) and the standing long jump (5.4 cm, 95% CI: 0.9 to 9.9).
Between August 2015 and November 2019, 30 workshops were delivered, with 468 teachers from 249 schools in attendance. The characteristics of these schools are presented in Table 5. Most schools included grades 7–12 (traditional secondary school format), however some were split junior (grades 7–9 or 7–10) or senior (grades 10–12 or 11–12) campuses. Three of the adopting schools had atypical grade ranges (i.e., grades 3–12 and 5–8), as well as one primary (elementary; kindergarten to grade 6) school. Forty-six schools were fully or partially selective/specialist, and over 90% were Government funded schools. The 213 Government secondary schools that adopted RT for Teens represent almost half of all Government secondary schools in NSW . Almost 70% of schools were located in major cities, whilst close to a quarter were from inner regional areas. The remaining 20% were in outer regional and remote areas. Participating schools’ mean ISCEA percentile was below the median (40%), ranging from the 2nd to 99th percentile. In addition to teachers from the aforementioned schools, eight employees from the NSW DoE School Sport Unit and the NSW Health Population Health research team attended workshops. This brings the total number of trained individuals to 476. Of these individuals, 429 (90%) completed a survey prior to attendance at the workshop to collect baseline demographic characteristics. Baseline characteristics of workshop attendees are presented in Supplementary Table 2. The majority of teachers were male, aged 26–30, and trained as a specialist PE teacher. Over half of the teachers did not have an additional qualification associated with fitness instruction, and average teaching experience was almost 12 years. Regarding adoption of the smartphone app, 144 of the 476 trained individuals created an app account (30%). At the school-level, 93/249 (37%) had at least one registered user (teacher and/or student). The number of users per school ranged from one to 335, with an average of 17 users per school.
During the dissemination evaluation, 22 lesson observations were conducted at the 17 schools within the effectiveness sub-sample. The level of implementation varied considerably across schools and is presented in Table 6. Resources were utilized in the majority of lessons, including the app and/or circuit cards. All lesson components (see Supplementary Table 1 and Supplementary Fig. 1a) were implemented to some degree, with the GymFit (i.e., development of RT skills) and high intensity resistance training (HIRT) workout the most prevalent. The behavioral messages and BoxFit (i.e., boxing style high intensity workout) were the least used components. Close to 60% of the 22 observed lessons included at least five of the suggested session components. Adherence to the SAAFE teaching principles was high, with Supportive and Active the most evident in sessions. Data from the RT for Teens app showed that of the 93 schools using the app, 48 used the workout function and 48 completed fitness testing. Thirty-five of the schools used both functions. In total, 2,336 workouts and 3,113 fitness tests were completed via the app.
Fifty-one of the 249 schools sent at least one additional teacher to a RT for Teens workshop (38 schools sent one additional teacher, 12 schools sent two additional teachers and one sent three additional teachers), demonstrating that these schools were engaged with the program and wanted to “upskill” additional staff members.
The objective of our study was to evaluate the reach, effectiveness, adoption, implementation and maintenance  of the RT for Teens program. Our conservative estimate suggests ~ 10,000 students were exposed to the program, representing substantial reach. Regarding effectiveness, the program improved muscular fitness, RT self-efficacy, perceived CRF and flexibility, and participation in muscle-strengthening physical activities in a sub-sample of students who completed the assessments. Adoption was high, with 468 teachers from 249 schools trained to deliver the program. These 249 schools include almost half of the Government secondary schools in NSW. Implementation varied considerably across schools, however, resources usage and adherence to the SAAFE principles was evident in most sessions. A fifth of schools sent one or more teachers to subsequent workshops for training, indicating potential program maintenance in schools. To our knowledge, this is the first study focusing on the state-wide dissemination of a school-based RT program.
Previous studies have utilized a variety of methods to calculate the ‘potential’ reach of school-based physical activity interventions . Similar to the current study, two interventions [60, 61] utilized teacher workshop enrollments to estimate potential reach into the student population. Others have used school enrollment numbers [62, 63], and ordering of program materials  as the method of calculation. Given the difficulty in collecting student participation data from teachers and schools at-scale, teacher workshop enrollment data was utilized as the method to estimate reach into the student population in the current study. Based on a conservative estimate that each teacher delivered the program to one class of students at their school, we estimated reach to be 10,000 students (5% of total student population). While it is possible that some teachers did not deliver the RT for Teens program to any of their classes, others may have delivered the program to multiple classes over a number of years since receiving the training (which commenced in 2015). As such, our estimate is likely to be an underestimation of actual student reach. Findings from semi-structured interviews conducted with teachers  support this notion, as teachers identified a variety of delivery methods, including during school sport, compulsory PE, and elective PE classes.
Of note, the RT for Teens program was also included in the Physical Activity 4 Everyone (PA4E1) whole-school intervention (as the enhanced school sport component) . At least one teacher from each of the 24 PA4E1 program schools received the RT for Teens training  (these teachers are included in the aforementioned total of 468 trained teachers) . Schools were instructed to deliver RT for Teens for 10-weeks to at least one full grade level of students , with 83% of schools achieving this at 12-months. With the inclusion of these schools, and the full grade of participating students, further support is provided for the potential underestimation of aforementioned reach into the student population.
Within the reach domain, it is also important to assess the characteristics of participants, to describe the representativeness of the population and thus the generalizability of findings . This is important during at-scale delivery of population health interventions. The proportion of females within RT for Teens dissemination cohort, effectiveness sub-sample school cohort, and effectiveness sub-sample student cohort (all ~ 48%) was comparable to the 49% of female students reported across the NSW DoE . Additionally, data from the three RT for Teens groups indicates a slightly higher mean percentage of Indigenous students across the dissemination, effectiveness sub-sample school, and effectiveness sub-sample student cohorts. These cohorts reported 10%, 8% and 7% students of Indigenous heritage, respectively, compared to 6% of NSW students identify as being of Aboriginal or Torres Strait Islander descent . As such, these findings provide a positive insight into the availability of the RT for Teens program in schools with representative female and Indigenous student cohorts, however assumptions are preliminary, and limited due to available data.
There is considerable variability in the reporting of effectiveness data in programs delivered at-scale, with the majority reporting effectiveness from a prior study . In the Action Schools! BC trial, efficacy was determined prior to scale-up and alluded to in future publications [61, 62]. Studies carried out in the school setting  have also used the educators’ perceptions of effectiveness (i.e., teachers’ perceived impact on student outcomes). The collection of valid outcome measures at-scale is challenging and as such, mixed methods are encouraged . In addition to the quantitative data reported, semi-structured interviews aligned with RE-AIM were conducted with teachers to assess their perceptions of program impact. Findings from these interviews have been published previously . Briefly, teachers reported high levels of student enjoyment, engagement, and motivation during the program . The collection of student-level effectiveness data during the dissemination phase, via fitness tests and surveys , was an attempt to strengthen and support interview findings. Despite the lack of a control group to ascertain causality, the effectiveness findings from the dissemination can be interpreted in conjunction with those from our previous RCT . This method was used in a recent systematic review to determine the scale-up penalty that occurs when interventions progress from efficacy to effectiveness to dissemination . Of note, improvements in muscular fitness were slightly larger in the current study when compared to results from our previous RCT . Considering the decreased effect often seen in scaled-up interventions (~ 60% scale-up penalty) , the effects observed in our effectiveness sub-sample are promising. However, due to the teacher-led collection of data in a number of schools, findings should be interpreted with a degree of caution. Whilst teachers were provided with instructions for fitness testing, and have been shown to conduct valid and reliable fitness testing , their level of training and commitment to rigor was likely lower than that of the research team. Additionally, a number of schools did not provide complete fitness data, which may have impacted our results. While lack of time was the main barrier to fitness testing, it is also possible that teachers may have forgotten to conduct tests and/or report results.
We operationalized adoption as the number of schools with at least one teacher who had participated in the RT for Teens professional learning workshop. A total of 468 teachers from 249 schools, including 213 Government secondary schools, had at least one RT for Teens trained teacher. Similar school numbers have been seen in previous successful school-based programs delivered at-scale, including SPARK PE . A recent review  highlighted that ‘social influences’, such as support (or lack of) from school boards, is one of the most highly cited facilitators/barriers to the implementation (and preceding adoption) of school-based physical activity programs and policies. This finding provides a potential explanation for the adoption of RT for Teens in almost half of NSW government secondary schools . The RT for Teens workshop was provided as accredited professional learning in partnership with the NSW DoE, with teachers gaining hours towards their mandated training requirements. In addition to this social influence, the partnership with the NSW DoE also allowed for co-creation of the adapted program. The research team utilized feedback from the DoE when adapting RT for Teens from the previous NEAT Girls  and ATLAS  programs. Co-creation is a necessary step when designing for dissemination, to maximize the contextual appropriateness of a program for a setting . It is important that the needs of the stakeholders are met, to maximize adoption potential.
There was noticeable variation in implementation across schools. Of note, the overall session score within the dissemination (5/10) was lower than observed within the RCT (7/10) . Despite the variations in delivery, the majority of lessons still included many of the key RT for Teens program components. The necessary focus on muscular fitness  remained (see Supplementary Table 1 and Supplementary Fig. 1a), as GymFit and HIRT workouts were the most commonly included components. Interview findings supported this observation, as teachers noted the increased incorporation of RT activities into lessons . Variations in delivery during dissemination are not necessarily seen as a downfall, but rather a testament to the inbuilt flexibility of the program . It is likely that during the dissemination phase, rather than delivering all program components in each lesson, teachers selected parts that best suited their students and the available lesson time. It is important to note that variation in delivery may impact outcomes, as certain program components (and/or the amount of time committed) may have differential impacts on students’ RT skills and muscular fitness. Balancing the need for adaptability whilst maximizing program impact is a constant tension in dissemination research . Nonetheless, the effectiveness data from our sub-sample suggests the adaptations that may have occurred did not have an adverse impact on program outcomes, though this would need to be evaluated more rigorously to be certain.
The RT for Teens app was also a useful intervention resource, including fitness testing and workout functions. The current version of the app was only released in mid-2018, created in response to the reported barriers experienced with the earlier web-based version of the app . Whilst app data provide an objective measure of resource utilization, the reported number of workouts and fitness tests may not be a true indication of usage. Strategies discussed during the professional learning workshop included how to overcome barriers related to device usage and student access to smartphones. These included how to make hardcopies of workouts and printed pre-post student fitness tests. As such, teachers may have created an app account and produced these hard copy resources, which limits the ability to assess true utilization of the app. App usage may have also varied throughout program delivery as students became more familiar with RT exercises, therefore requiring less support from the app. This was evident during the RT for Teens RCT , as resource usage (including the app) declined during the second half of the intervention period (as noted during lesson observations).
Whilst there are a number of promising findings related to implementation, there is considerable room for improvement. Although our study was designed using an established scale-up evaluation framework (i.e., RE-AIM), we did not use an existing implementation framework (e.g., Consolidated Framework for Implementation Research)  or scale-up guide (e.g., PRACTical planning for Implementation and Scale-up) . In addition, our study was designed before publication of the Standards for Reporting Implementation Studies (StaRI) statement . In the time period since RT for Teens was designed and developed, there has been rapid increase in the publication of recommendations and guidelines for implementation research . Researchers now have added support to assist in the design, conduct and reporting of implementation trials than was available when the RT for Teens dissemination study was conceived.
Quality implementation of programs is linked with improved outcomes , so it is plausible that improvements in fidelity, would likely lead to greater improvements in student outcomes. Whilst program flexibility is a strength of RT for Teens, the lack of support following program training was a limitation. Our key learning from this study is that standalone professional learning workshops are not sufficient to support the high-quality implementation of physical activity programs in schools. External support from change agents is needed to overcome commonly faced barriers and enhance program implementation. The failure to provide on-going support may explain why ‘voltage drop’ occurs when interventions progress from small-scale projects with high levels of researcher support to larger-scale effective and dissemination studies with minimal researcher support. For example, one of the implementation strategies included within a recent school-based policy was to provided teachers with ongoing support . This was via face-to-face meetings and remote communication (email and phone), between support officers and in-school champions. Similarly, teachers delivering a program for senior students were provided with initial (professional learning) and ongoing (observation and feedback) support . Findings from these evaluations indicated that external support likely contributed to improvements in teachers’ implementation of the policy [78, 80, 81].
For the purpose of this study, maintenance was operationalized at the setting-level. School-level maintenance, or the integration of the program into practice (often referred to as institutionalization ), indicates that the intervention and implementation practices have been sustained. Long-term maintenance is dependent on teachers continuing implementation after the research evaluation period [82, 83]. Teacher-level factors such as confidence and understanding, along with perceived benefit to students, are important factors in determining implementation and maintenance of a program . The proportion of schools with teachers attending an additional workshop (after the first instance of teacher training) was utilized as a representation of program maintenance (i.e., institutionalization of the RT for Teens program). Following interest, and incorporation of RT for Teens into one teachers’ practice, there arose a need to train additional teachers to sustain program delivery. At the very least this is an indication of teachers’ satisfaction with the workshop, and their belief that it would be of value to other staff members at their school. Interview findings support this assumption , with teachers reporting they were likely to share program information and resources with staff once they returned to school. This included with individual teachers and/or entire faculties through in-school workshops . Individual-level (i.e., student) maintenance of program effects was demonstrated in the RCT , with muscular fitness and RT self-efficacy maintained at 12-months, however was not evaluated during the dissemination phase.
Strengths and limitations
Strengths of this study include the extensive involvement of the NSW DoE School Sport Unit. This partnership allowed for greater dissemination of the program throughout NSW secondary schools. The mixed methods of data collection, including interviews, also allowed for the utilization of a variety of data sources to evaluate dissemination. Rather than relying on single sources of information, the multiple methods allowed for a more in-depth exploration of program impact across RE-AIM domains. Evaluation of program effectiveness via the RCT, prior to at-scale dissemination, also contributed to the strength of this study. This data allowed for findings from the dissemination phase (where there was no control group) to be compared against outcome improvements from the rigorous RCT. Whilst this study had many strengths, it is not without limitations. Firstly, little implementation support was provided to teachers following the workshop, which may have hindered implementation efforts. Second, this lack of support/contact with schools also presented as a barrier to determine implementation quality and maintenance. Third, not all schools used the RT for Teens app. According to our usage data, participants completed 2,336 workouts and 3,116 fitness tests. These numbers are much lower than our estimated reach (i.e., ~ 10,000 students). Fourth, implementation findings were determined using data from a subset of participating teachers. Fifth, program acceptance data was not collected from students and teachers in the dissemination phase. However, findings from our RCT suggest that teachers were highly satisfied with the program (4.8/5) . Students’ overall satisfaction with the program was not quite as high (3.8/5) . Finally, evaluation of implementation quality and the impact of varied delivery methods on student-level outcomes was not explored.
Given the need to implement effective physical activity programs at-scale [22,23,24,25], our dissemination study provides an important contribution to the field. RT for Teens is the first school-based RT program to be delivered at-scale. Our study provides an in-depth account of the journey of the program through scale-up and describes the impact of the program across RE-AIM dimensions. The RT for Teens program had large potential reach and high levels of adoption, however, implementation varied considerably across schools. External support from change agents may be needed to overcome barriers and optimize intervention implementation in schools, including the documentation of adaptations that may have been made to increase implementation success. Future studies, guided by accepted frameworks, recommendations and guidelines [34, 75,76,77] for implementation research are needed. These will further explore and evaluate the impact and cost-effectiveness of RT interventions in schools, with a greater focus on the impact of implementation support on implementation quality and program maintenance.
Availability of data and materials
Study data and materials are not available publicly, however may be available upon request to the lead investigators. All consenting participants were issued a unique identification number for confidentiality, and all data is stored securely as per ethical requirements.
Active Teen Leaders Avoiding Screen-time
Behavioral Regulations in Exercise Questionnaire-2
Department of Education
High intensity resistance training
International Fitness Scale
Nutrition and Enjoyable Activity for Teen
New South Wales
Physical Activity 4 Everyone
Randomized controlled trial
Reach, effectiveness, adoption, implementation, maintenance
Supportive, active, autonomous, fair and enjoyable
Kim Y, Wijndaele K, Lee D-C, Sharp SJ, Wareham N, Brage S. Independent and joint associations of grip strength and adiposity with all-cause and cardiovascular disease mortality in 403,199 adults: the UK Biobank study. Am J Clin Nutr. 2017;106(3):773–82.
Smith JJ, Eather N, Morgan PJ, Plotnikoff RC, Faigenbaum AD, Lubans DR. The health benefits of muscular fitness for children and adolescents: a systematic review and meta-analysis. Sports Med. 2014;44(9):1209–23.
World Health Organization. Recommended Population Levels of Physical Activity for Health: 5–17 Years Old. Switzerland: WHO; 2010.
Centers for Disease Control & Prevention. High school youth risk behavior surveillance system. 2019.
Australian Bureau of Statistics. National Health Survey: first results, 2017–18. 2018.
Carlson SA, Fulton JE, Schoenborn CA, Loustalot F. Trend and prevalence estimates based on the 2008 Physical Activity Guidelines for Americans. Am J Prev Med. 2010;39(4):305–13.
Bennie JA, De Cocker K, Smith JJ, Wiesner GH. The epidemiology of muscle-strengthening exercise in Europe: A 28-country comparison including 280,605 adults. PLoS ONE. 2020;15(11):e0242220.
Bennie JA, Pedisic Z, van Uffelen JG, Charity MJ, Harvey JT, Banting LK, et al. Pumping iron in Australia: prevalence, trends and sociodemographic correlates of muscle strengthening activity participation from a national sample of 195,926 adults. PLoS One. 2016;11(4):e0153225.
Australian Department of Health. Australia’s physical activity & sedentary behaviour guidelines for adults (18–64 years). 2019.
World Health Organization. Recommended Levels of Physical Activity for adults aged 18–64 years. Switzerland: WHO; 2010.
Piercy KL, Troiano RP, Ballard RM, Carlson SA, Fulton JE, Galuska DA, et al. The physical activity guidelines for Americans. JAMA. 2018;320(19):2020–8.
Rhodes RE, Lubans DR, Karunamuni N, Kennedy S, Plotnikoff R. Factors associated with participation in resistance training: a systematic review. Br J Sports Med. 2017;51(20):1466–72.
Tannehill D, MacPhail A, Walsh J, Woods C. What young people say about physical activity: the Children's Sport Participation and Physical Activity (CSPPA) study. Sport Educ Soc. 2015;20(4):442–62.
ten Hoor G, Sleddens EF, Kremers SP, Schols AM, Kok G, Plasqui G. Aerobic and strength exercises for youngsters aged 12 to 15: what do parents think? BMC Public Health. 2015;15(1):994.
Smith JJ, Diallo TM, Bennie JA, Tomkinson GR, Lubans DR. Factors associated with adherence to the muscle-strengthening activity guideline among adolescents. Psychol Sport Exerc. 2020;51:101747.
Naylor P-J, Nettlefold L, Race D, Hoy C, Ashe MC, Higgins JW, et al. Implementation of school based physical activity interventions: a systematic review. Prev Med. 2015;72:95–115.
Nathan N, Elton B, Babic M, McCarthy N, Sutherland R, Presseau J, et al. Barriers and facilitators to the implementation of physical activity policies in schools: a systematic review. Prev Med. 2018;107:45–53.
Steele J, Fisher J, Skivington M, Dunn C, Arnold J, Tew G, et al. A higher effort-based paradigm in physical activity and exercise for public health: making the case for a greater emphasis on resistance training. BMC Public Health. 2017;17(1):1–8.
Cox A, Fairclough SJ, Kosteli M-C, Noonan RJ. Efficacy of school-based interventions for improving muscular fitness outcomes in adolescent boys: A systematic review and meta-analysis. Sports Med. 2020;50(3):543–60.
Dorgo S, King GA, Candelaria N, Bader JO, Brickey GD, Adams CE. The effects of manual resistance training on fitness in adolescents. J Strength Cond Res. 2009;23(8):2287.
Velez A, Golem DL, Arent SM. The impact of a 12-week resistance training program on strength, body composition, and self-concept of Hispanic adolescents. J Strength Cond Res. 2010;24(4):1065–73.
Reis RS, Salvo D, Ogilvie D, Lambert EV, Goenka S, Brownson RC, et al. Scaling up physical activity interventions worldwide: stepping up to larger and smarter approaches to get people moving. The Lancet. 2016;388(10051):1337–48.
Owen N, Glanz K, Sallis JF, Kelder SH. Evidence-based approaches to dissemination and diffusion of physical activity interventions. Am J Prev Med. 2006;31(4):35–44.
Lewis BA, Napolitano MA, Buman MP, Williams DM, Nigg CR. Future directions in physical activity intervention research: expanding our focus to sedentary behaviors, technology, and dissemination. J Behav Med. 2017;40(1):112–26.
McKenzie TL, Sallis JF, Rosengard P, Ballard K. The SPARK programs: a public health model of physical education research and dissemination. J Teach Phys Educ. 2016;35(4):381–9.
Glasgow RE, Klesges LM, Dzewaltowski DA, Bull SS, Estabrooks P. The future of health behavior change research: what is needed to improve translation of research into health promotion practice? Ann Behav Med. 2004;27(1):3–12.
Durlak JA, DuPre EP. Implementation matters: A review of research on the influence of implementation on program outcomes and the factors affecting implementation. Am J Community Psychol. 2008;41(3–4):327–50.
Milat AJ, King L, Bauman AE, Redman S. The concept of scalability: increasing the scale and potential adoption of health promotion interventions into policy and practice. Health Promot Int. 2013;28(3):285–98.
Glasgow RE, Vogt TM, Boles SM. Evaluating the public health impact of health promotion interventions: the RE-AIM framework. Am J Public Health. 1999;89(9):1322–7.
Glasgow RE, Klesges LM, Dzewaltowski DA, Estabrooks PA, Vogt TMJ. Evaluating the impact of health promotion programs: using the RE-AIM framework to form summary measures for decision making involving complex issues. Health Educ Res. 2006;21(5):688–94.
Dewar DL, Morgan PJ, Plotnikoff RC, Okely AD, Collins CE, Batterham M, et al. The Nutrition and Enjoyable Activity for Teen girls study: a cluster randomized controlled trial. Am J Prev Med. 2013;45(3):313–7.
Smith JJ, Morgan PJ, Plotnikoff RC, Dally KA, Salmon J, Okely AD, et al. Smart-phone obesity prevention trial for adolescent boys in low-income communities: the ATLAS RCT. Pediatrics. 2014;134(3):e723–e731.
Lubans DR, Morgan PJ, Okely AD, Dewar D, Collins CE, Batterham M, et al. Preventing obesity among adolescent girls: one-year outcomes of the Nutrition and Enjoyable Activity for Teen Girls (NEAT Girls) cluster randomized controlled trial. Arch Pediatr Adolesc Med. 2012;166(9):821–7.
Damschroder LJ, Aron DC, Keith RE, Kirsh SR, Alexander JA, Lowery JC. Fostering implementation of health services research findings into practice: a consolidated framework for advancing implementation science. Implement Sci. 2009;4(1):50.
Wolfenden L, Bolsewicz K, Grady A, McCrabb S, Kingsland M, Wiggers J, et al. Optimisation: defining and exploring a concept to enhance the impact of public health initiatives. Health Res Policy Syst. 2019;17(1):1–13.
Kennedy SG, Smith JJ, Morgan PJ, Peralta LR, Hilland TA, Eather N, et al. Implementing Resistance Training in Secondary Schools: A Cluster RCT. Med Sci Sports Exerc. 2018;50:62–72.
Indig D, Lee K, Grunseit A, Milat A, Bauman A. Pathways for scaling up public health interventions. BMC Public Health. 2018;18(1):68.
Kennedy SG, Peralta LR, Lubans DR, Foweather L, Smith JJ. Implementing a school-based physical activity program: process evaluation and impact on teachers’ confidence, perceived barriers and self-perceptions. Phys Educ Sport Pedagogy. 2019;24(3):233–48.
Lubans DR, Morgan PJ, Dewar D, Collins CE, Plotnikoff RC, Okely AD, et al. The Nutrition and Enjoyable Activity for Teen Girls (NEAT girls) randomized controlled trial for adolescent girls from disadvantaged secondary schools: rationale, study protocol, and baseline results. BMC Public Health. 2010;10(1):652.
Lubans DR, Smith JJ, Peralta LR, Plotnikoff RC, Okely AD, Salmon J, et al. A school-based intervention incorporating smartphone technology to improve health-related fitness among adolescents: rationale and study protocol for the NEAT and ATLAS 2.0 cluster randomised controlled trial and dissemination study. BMJ Open. 2016;6(6).
Smith JJ, Morgan PJ, Plotnikoff RC, Dally KA, Salmon J, Okely AD, et al. Rationale and study protocol for the ‘Active Teen Leaders Avoiding Screen-time’(ATLAS) group randomized controlled trial: an obesity prevention intervention for adolescent boys from schools in low-income communities. Contemp Clin Trials. 2014;37(1):106–19.
Curran GM, Bauer M, Mittman B, Pyne JM, Stetler C. Effectiveness-implementation hybrid designs: combining elements of clinical effectiveness and implementation research to enhance public health impact. Med Care. 2012;50(3):217-26.
Shaw RB, Sweet SN, McBride CB, Adair WK, Ginis KAM. Operationalizing the reach, effectiveness, adoption, implementation, maintenance (RE-AIM) framework to evaluate the collective impact of autonomous community programs that promote health and well-being. BMC Public Health. 2019;19(1):1–14.
Sutherland RL, Nathan NK, Lubans DR, Cohen K, Davies LJ, Desmet C, et al. An RCT to facilitate implementation of school practices known to increase physical activity. Am J Prev Med. 2017;53(6):818–28.
Cooper Institute for Aerobics Research. The Prudential FITNESSGRAM® test administration manual. Dallas: The Cooper Institute for Aerobic Research; 1992.
Castro-Piñero J, Ortega FB, Artero EG, Girela-Rejón MJ, Mora J, Sjöström M, et al. Assessing muscular strength in youth: usefulness of standing long jump as a general index of muscular fitness. J Strength Cond Res. 2010;24(7):1810–7.
Sánchez-López M, Martínez-Vizcaíno V, García-Hermoso A, Jiménez-Pavón D, Ortega F. Construct validity and test–retest reliability of the I nternational F itness S cale (IFIS) in S panish children aged 9–12 years. Scand J Med Sci Sports. 2015;25(4):543–51.
Lubans DR, Morgan P, Callister R, Plotnikoff RC, Eather N, Riley N, et al. Test-retest reliability of a battery of field-based health-related fitness measures for adolescents. J Sports Sci. 2011;29(7):685–93.
Markland D, Tobin V. A modification to the behavioural regulation in exercise questionnaire to include an assessment of amotivation. J Sport Exercise Psy. 2004;26(2):191–6.
Scott JJ, Morgan PJ, Plotnikoff RC, Lubans DR. Reliability and validity of a single-item physical activity measure for adolescents. J Paediatr Child Health. 2015;51(8):787–93.
Martínez-Gómez D, Welk G, Puertollano M, Del-Campo J, Moya J, Marcos A, et al. Associations of physical activity with muscular fitness in adolescents. Scand J Med Sci Sports. 2011;21(2):310–7.
Lubans DR, Lonsdale C, Cohen K, Eather N, Beauchamp MR, Morgan PJ, et al. Framework for the design and delivery of organized physical activity sessions for children and adolescents: rationale and description of the ‘SAAFE’teaching principles. Int J Behav Nutr Phys Act. 2017;14(1):1–11.
Shelton RC, Lee M, Brotzman LE, Wolfenden L, Nathan N, Wainberg ML. What is dissemination and implementation science?: An introduction and opportunities to advance behavioral medicine and public health globally. Int J Behav Med. 2020;27(1):3–20.
Rabin BA, Brownson RC, Haire-Joshu D, Kreuter MW, Weaver NL. A glossary for dissemination and implementation research in health. J Public Health Manag Pract. 2008;14(2):117–23.
Brownson RC, Colditz GA, Proctor EK. Dissemination and implementation research in health: translating science to practice. New York: Oxford University Press; 2017.
NSW Department of Education. Class size 2019 [Available from: https://education.nsw.gov.au/about-us/our-people-and-structure/history-of-government-schools/facts-and-figures/class-size.
NSW Department of Education. Aboriginal students in NSW Public Schools Annual Report 2014. In: Department of Education, editor. 2015.
NSW Department of Education.2019 Secondary Education Schools 2019 [Available from: https://data.cese.nsw.gov.au/data/dataset/secondary-education-schools-by-selective-specialist-and-co-educational-status/resource/0bdbf52b-c71b-475e-b3ce-3f3d65b1a0ee.
Kennedy SG, Sanders T, Estabrooks PE, Smith JJ, Lonsdale C, Foster C, et al. Implementation at-scale of school-based physical activity interventions: A systematic review utilizing the RE-AIM framework. Obes Rev. 2021:doi: https://doi.org/10.1111/obr.13184.
McKenzie TL, Sallis JF, Rosengard P. Beyond the stucco tower: Design, development, and dissemination of the SPARK physical education programs. Quest. 2009;61(1):114–27.
McKay HA, Macdonald HM, Nettlefold L, Masse LC, Day M, Naylor P-J. Action Schools! BC implementation: from efficacy to effectiveness to scale-up. Br J Sports Med. 2015;49(4):210–8.
Mâsse LC, McKay H, Valente M, Brant R, Naylor P-J. Physical activity implementation in schools: a 4-year follow-up. Am J Prev Med. 2012;43(4):369–77.
Welk GJ, Bai Y, Saint-Maurice PF, Allums-Featherston K, Candelaria N. Design and evaluation of the NFL PLAY 60 FITNESSGRAM® Partnership Project. Res Q Exerc Sport. 2016;87(1):1–13.
Hoelscher DM, Kelder SH, Murray N, Cribb PW, Conroy J, Parcel GS. Dissemination and adoption of the Child and Adolescent Trial for Cardiovascular Health (CATCH): a case study in Texas. J Publ Health Manage Pract. 2001;7(2):90–100.
Kennedy SG, Smith JJ, Hansen V, Lindhout MI, Morgan PJ, Lubans DR. Implementing resistance training in secondary schools: an exploration of teachers' perceptions. Transl J Am Coll Sports Med. 2018;3(12):85–96.
Sutherland R, Campbell E, Nathan N, Wolfenden L, Lubans DR, Morgan PJ, et al. A cluster randomised trial of an intervention to increase the implementation of physical activity practices in secondary schools: study protocol for scaling up the Physical Activity 4 Everyone (PA4E1) program. BMC Public Health. 2019;19(1):883.
Sutherland R, Campbell E, McLaughlin M, Nathan N, Wolfenden L, Lubans DR, et al. Scale-up of the Physical Activity 4 Everyone (PA4E1) intervention in secondary schools: 12-month implementation outcomes from a cluster randomized controlled trial. Int J Behav Nutr Phys Act. 2020;17(1):1–14.
Smedegaard S, Brondeel R, Christiansen LB, Skovgaard T. What happened in the ‘Move for Well-being in School’: a process evaluation of a cluster randomized physical activity intervention using the RE-AIM framework. Int J Behav Nutr Phys Act. 2017;14(1):159.
Kessler RS, Purcell EP, Glasgow RE, Klesges LM, Benkeser RM, Peek C. What does it mean to “employ” the RE-AIM model? Eval Health Prof. 2013;36(1):44–66.
McCrabb S, Lane C, Hall A, Milat A, Bauman A, Sutherland R, et al. Scaling-up evidence-based obesity interventions: a systematic review assessing intervention adaptations and effectiveness and quantifying the scale-up penalty. Obes Rev. 2019;20(7):964–82.
Lane C, McCrabb S, Nathan N, Naylor P-J, Bauman A, Milat A, et al. How effective are physical activity interventions when they are scaled-up: a systematic review. Int J Behav Nutr Phys Act. 2021;18(1):1–11.
Morrow JR Jr, Martin SB, Jackson AW. Reliability and validity of the FITNESSGRAM®: Quality of teacher-collected health-related fitness surveillance data. Res Q Exerc Sport. 2010;81(sup3):S24–30.
Dowda M, Sallis JF, McKenzie TL, Rosengard P, Kohl HW III. Evaluating the sustainability of SPARK physical education: a case study of translating research into practice. Res Q Exerc Sport. 2005;76(1):11–9.
Kennedy SG, McKay HA, Naylor PJ, Lubans DR. Implementation and scale-up of school-based physical activity interventions. The Routledge Handbook of Youth Physical Activity. New York and Oxon: Routledge; 2020. p. 438–60.
Koorts H, Eakin E, Estabrooks P, Timperio A, Salmon J, Bauman A. Implementation and scale up of population physical activity interventions for clinical and community settings: the PRACTIS guide. Int J Behav Nutr Phys Act. 2018;15(1):1–11.
Pinnock H, Barwick M, Carpenter CR, Eldridge S, Grandes G, Griffiths CJ, et al. Standards for reporting implementation studies (StaRI) statement. BMJ. 2017;356.
Wolfenden L, Foy R, Presseau J, Grimshaw JM, Ivers NM, Powell BJ, et al. Designing and undertaking randomised implementation trials: guide for researchers. BMJ. 2021;372.
Nathan NK, Sutherland RL, Hope K, McCarthy NJ, Pettett M, Elton B, et al. Implementation of a school physical activity policy improves student physical activity levels: outcomes of a cluster-randomized controlled trial. J Phys Act Health. 2020;1:1–10.
Leahy AA, Eather N, Smith JJ, Hillman C, Morgan PJ, Nilsson M, et al. School-based physical activity intervention for older adolescents: rationale and study protocol for the Burn 2 Learn cluster randomised controlled trial. BMJ Open. 2019;9(5):e026029.
Kennedy SG, Leahy AA, Smith JJ, Eather N, Hillman CH, Morgan PJ, et al. Process evaluation of a school-based high-intensity interval training program for older adolescents: the burn 2 learn cluster randomised controlled trial. Children. 2020;7(12):299.
Lubans DR, Smith JJ, Eather N, Leahy AA, Morgan PJ, Lonsdale C, et al. Time-efficient intervention to improve older adolescents’ cardiorespiratory fitness: findings from the ‘Burn 2 Learn’cluster randomised controlled trial. Br J Sports Med. 2021;55:751–8.
Hung TTM, Chiang VCL, Dawson A, Lee RLT. Understanding of factors that enable health promoters in implementing health-promoting schools: a systematic review and narrative synthesis of qualitative evidence. PLoS One. 2014;9(9).
Langford R, Bonell C, Jones H, Pouliou T, Murphy S, Waters E, et al. The World Health Organization’s health promoting schools framework: a cochrane systematic review and meta-analysis. BMC Public Health. 2015;15(1):130.
The authors would like to thank the participating schools, students and teachers for their support and cooperation throughout the project.
This project is funded by the New South Wales Department of Education School Sport Unit (NSW DoE SSU) and the Australian Research Council. The NSW DoE SSU were program partners, involved in the co-creation of the RT for Teens program. Neither funding bodies had any role in the analysis of data, interpretation of data and dissemination of findings.
Ethics approval and consent to participate
Ethics approval was obtained from the human research ethics committees of the University of Newcastle, Australia (H-2014–0312) and NSW DoE (SERAP: 2012121). Written informed consent was obtained from all school Principals and teachers. Study participants and their parents/caregivers were provided with information statements and opt-out consent was applied.
Consent for publication
The authors declare that they have no competing interests.
Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.
The original version of this article was revised: the name and affiliation have been updated.
Additional file 1: Supplementary Table 1
. Proposed RT for Teens session structure.
Additional file 2: Supplementary Table 2
. Characteristics of workshop attendees.
Additional file 3
: The TIDieR (Template for Intervention Description and Replication) Checklist*.
Additional file 4: Supplementary Figure 1a
. RT for Teens session observation checklist (page 1, session components). Supplementary Figure 1b. RT for Teens session observation checklist (page 2, SAAFE adherence).
Additional file 5: Supplementary Figure 2
. RT for Teens exercise library examples (from App).
Rights and permissions
Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material in this article are included in the article's Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article's Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit http://creativecommons.org/licenses/by/4.0/. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated in a credit line to the data.
About this article
Cite this article
Kennedy, S.G., Smith, J.J., Estabrooks, P.A. et al. Evaluating the reach, effectiveness, adoption, implementation and maintenance of the Resistance Training for Teens program. Int J Behav Nutr Phys Act 18, 122 (2021). https://doi.org/10.1186/s12966-021-01195-8
- Muscular fitness
- Physical activity