title: Development and evaluation of a home-based physical activity intervention for adolescent girls - The HERizon Project
Creators: name: Cowley, E
Publisher: name: Liverpool John Moores University
Year: 2022

description: Approximately 80% of adolescent girls in the UK and Ireland are not meeting the minimum daily PA guidelines recommended to improve health and wellbeing. The majority of past interventions targeting this population have been school-based, but few have had sustained positive effects on physical activity (PA). As perceived low competence and fear of judgement by others are primary barriers to girls' participation in PA, it is thought that interventions that are based in settings where the individual feels safe and comfortable, such as in the home, will likely lead to more effective improvements in PA. This thesis aimed to develop and assess a home-based intervention to increase PA in adolescent girls in accordance with the Medical Research Council guidance which involved the active involvement of adolescent girls in intervention design to improve its acceptability, feasibility, and enjoyability for this population. Study 1 explored adolescent girls' perspectives of PA and the perceived influence of gender through 8 focus groups (n = 48) in Ireland and the UK. Focus groups were thematically analysed and interpreted within a socioecological framework. Within the intrapersonal level, fear of judgement and changing priorities were identified as key barriers. Social pressure and having support from others were recognised as interpersonal factors affecting PA. Across all focus groups, gender inequality and social gender stereotyping were identified as major barriers preventing regular PA participation. The findings of this study directly informed the development of the HERizon Project and suggest that interventions targeting adolescent girls’ PA should provide girls with independence to choose when and where they are physically active, encourage social support through online group communities and workout classes, and encourage girls to try new types of PA that have been traditionally categorised as ‘male’ activities, e.g., boxing and weightlifting. Study 2 was a randomised wait-list controlled trial that aimed to formatively evaluate the HERizon intervention. HERizon was a six week home-based multi-component PA intervention that was developed using self-determination theory and provided participants with behaviour change support through weekly Activity Mentor phone calls. Participants (mean 14.2 years, SD 1.1) were randomised into the HERizon intervention group (n = 22) and a usual care waitlist control group (n = 20). At postintervention, there was no significant difference found in self-reported moderate to vigorous physical activity (MVPA) between groups, however the intervention group had significantly increased cardiorespiratory fitness, muscular endurance, intrinsic motivation, and body appreciation. There was high retention and adherence to the PA intervention. Qualitative results indicated that participants found HERizon to be enjoyable and acceptable. Future research was required to ascertain which components of the HERizon intervention were most effective and enjoyable, and a larger sample size using device-based measures of PA is needed to further evaluate the intervention’s effectiveness on increasing adolescent girls' PA. Study 3 involved a process evaluation of a mixed-methods, four-arm pilot randomised controlled trial of the HERizon intervention, aimed at increasing adolescent girls’ PA. The 12 week study explored the reach, recruitment, fidelity, adherence and context of the remote intervention, as well as investigating mechanisms of impact and acceptability of intervention components. Participants were randomly allocated to one of four groups; PA programme group (n = 36), behaviour change support group (n = 44), combined group (n = 34), and comparison group (n = 40). Results found high fidelity for delivery and receipt, as well as high participant adherence and satisfaction across all intervention arms. For the PA programme and combined groups, it was recommended that the online social media community be improved for a definitive future trial. Groups that received behaviour change support from an Activity Mentor were also found to have high satisfaction and engagement. Qualitative results from all intervention arms found autonomy, accountability and routine to be facilitators to increasing girls’ PA levels. This process evaluation provided insight into the acceptability and feasibility of implementing the HERizon intervention in a real-world setting. To assess HERizon’s effectiveness, PA and secondary outcomes measures should be assessed in subsequent studies outside of the COVID-19 circumstance. The findings of the studies included in this PhD give detailed insight into the many factors that influence adolescent girls’ PA. It further provides support for remote PA interventions as the home was found to be an appropriate and effective setting in improving adolescent girls' PA behaviours. Through detailed process evaluations, understanding has been gained on intervention fidelity which helped to provide greater meaning to quantitative results. By considering the context in which the interventions are being carried out, more appropriate and accurate conclusions could be made on intervention effectiveness, acceptability and appropriateness.