This mixed-method observational study will compare the short- and long-term effectiveness of two different delivery approaches of an exercise referral scheme (Exercise for Health, EFH). As the intervention is already in widespread use randomisation is not feasible, therefore a case control design is adopted to compare the effectiveness of an adapted EFH scheme (delivered at centre A) with the standard EFH scheme (delivered at centre B). Centre B is selected as the comparison centre due to its similarity to centre A on socio-demographic markers (e.g. number of EFH referrals, socioeconomic make-up of local population).