A cluster randomised controlled trial to investigate the effectiveness and cost effectiveness of the ‘Girls Active’ intervention

Background to the study

Despite the health benefits of physical activity, data from the UK suggest that a large proportion of adolescents do not meet the recommended levels of moderate-to-vigorous physical activity (MVPA). This is particularly evident in girls, who are less active than boys across all ages and display a faster rate of decline in physical activity throughout adolescence. Furthermore, a large drop in the proportion of girls meeting MVPA guidelines occurs during and following the transition to secondary school (age 11+). Reported barriers for girls’ participation include body image issues, embarrassment, skill, perceptions about physical activity being too competitive and a perceived lack of support.

The ‘Girls Active’ intervention has been designed by the Youth Sport Trust to target the lower participation rates observed in adolescent girls, specifically girls aged 11-14 years. Girls Active is focused on providing a support framework (through training for teachers and peer leadership, resources, mentorship) to schools to review their physical activity, sport and PE provision, culture and practices to ensure they are relevant and attractive to their 11–14 year old girls.

Schools can develop their own tailored approach to tackling the issues of lower participation among girls. Furthermore, it uses leadership and peer marketing groups (consisting of adolescent girl volunteers) to empower girls to influence decision making in their school, increase their own participation, develop as role models and ‘sell’ physical activity to other girls.

What does the study involve?

The University of Leicester, in collaboration with Loughborough University, University of Stirling and Bangor University, will evaluate the effectiveness and cost-effectiveness of Girls Active in 20 secondary schools (involving 1600 adolescent girls) the East and West Midlands. Baseline, 7 and 14 month measures will be taken to evaluate effectiveness. Time spent in moderate-to-vigorous physical activity (MVPA), measured by a wrist worn accelerometer (GENEActiv) at 14 months, will be the primary outcome and secondary outcomes will include percentage achieving MVPA guidelines, total volume of physical activity (i.e. all movement), sedentary behaviour, body composition and a number of psycho-social variables (e.g., motivation, attitudes, enjoyment and social support for physical activity).

Further Information

If you would like further information about this study please contact

Dr Charlotte Edwardson ce95@le.ac.uk or

Dr Deirdre Harrington dh204@le.ac.uk


 A cluster randomised controlled trial to investigate the effectiveness and cost effectiveness of the ‘Girls Active’ intervention: a study protocol