Strategies for recruitment of adolescent girls into physical activity programmes: a systematic review and regression analysis

Globally, adolescent girls are one of the least active populations, with ~ 15% meeting WHO physical activity (PA) guidelines. This review offers the first quantitative synthesis of recruitment rates into PA randomised controlled trials targeting adolescent girls and identifies strategies which appear most promising, providing actionable guidance for PA providers and researchers. Five databases were searched, supplemented by citation hand-searches. Eligible studies were randomised controlled trials of girls aged 10–19 years with PA interventions lasting ≥ 4 weeks that reported recruitment rates or pre-determined recruitment goals; studies limited to clinical populations or athletes were excluded. Descriptive statistics were used to calculate mean recruitment rates overall and by subgroups such as age, socioeconomic status, and programme setting, while correlation and regression analyses examined associations between recruitment strategies and recruitment outcomes. Fifteen thousand one hundred records were identified; 37 through citation search. After removing duplicates (n = 8,603), 6,407 records were screened by title and abstract and 134 full texts assessed. Following consensus, 27 studies were included; 23/27 were school-based. The mean recruitment rate was 62.6% (± 27.8), decreasing to 56.5% (± 35.0) in low-SES populations. Incomplete reporting of the recruitment funnel was common. Recruitment was higher amongst younger (65.9% ± 26.7) versus older (51.2% ± 32.1) girls. Teacher involvement was associated with improved recruitment: when teachers were financially supported to organise activities (R2 = 0.44, p = 0.005) or followed up for consent with absent girls (R2 = 0.25, p = 0.048). Recruitment goals were achieved in 68% of studies, particularly those using researcher presentations or PA taster sessions (r = 0.52, p = 0.041). School-based programmes during class time recruited more effectively (62.3% ± 28.1) than those offered at optional times (54.9% ± 30.9). Incentives for girls was associated with the lowest recruitment rates (51.2% ± 32.1) and reduced retention (R2 = 0.39, p = 0.024). Mean retention was high (84.9% ± 13.3); better in school-based (86.0% ± 12.6) versus non-school-based (81.2% ± 16.3) programmes and improved when fitness assessments were included (R2 = 0.24, p = 0.020). Recruiting adolescent girls into PA programmes is feasible but challenging. Teacher engagement, integrating PA into school timetables, and interactive approaches (presentations, tasters) emerged as potentially promising strategies for recruiting girls, though the evidence base was predominantly school-based and reporting of recruitment strategies was often incomplete.