Abstract
Parkrun is a free, weekly, timed 5 km run or walk with the aim of creating 'a healthier, happier planet'. The aim of this study is to use a survey of parkrun to create a model of life satisfaction that can be used by other initiatives seeking (1) to evaluate them using the WELLBY approach, and (2) to create logic models for change in life satisfaction. A cross-sectional survey was sent in autumn 2024-967,478 UK parkrunners producing 78,662 responses. A model was hypothesised and tested using non-linear multiple stepwise regression analysis. Health status was found to have a very large non-linear effect on life satisfaction, primarily related to mental health. Life satisfaction was moderated by age, time registered with parkrun, gender, activity level and index of multiple deprivation. Change in activity level following parkrun participation was found to have a small effect, while the number of runs or walks completed per person had a very small effect. Estimated economic benefits of parkrun to the UK economy were estimated to be £668m. This included £75m for the number of runs or walks completed (£1.92 per run or walk per person), £132m for the increase in activity after participation, and £463m for an estimated improvement to health status of 3% (found in a previous study). The benefit-cost ratio was 53:1 if the estimated increase to health status was included and 16:1 if it was ignored. In terms of health promotion, the model suggested that life satisfaction could be increased most by focussing on sub-populations in the following order: those with very poor, poor and fair health status; those in early middle age; the least active; males; and those from deprived neighbourhoods. Finally, a protocol was described to allow initiatives to create their own simple logic models and their own evaluations.