The REACT exercise intervention
The overall structure of the REACT study intervention (including the behavioural maintenance element) is described elsewhere (The REACT study: generic structure (Week 1 to week 52).Each participant will receive a 45-min individualised, face-to-face introductory session which will be used to personalise the programme for starting levels and progressionTwo 60-min PA sessions per week, plus 15–20 min of social time, will then be delivered by the REACT trainerPedometers will be introduced during these sessions to support the participant in the transition to the maintenance phaseAfter week 12, the exercise session frequency is reduced to once per week but with an expectation that participants find an hour per week to exercise at home, in the neighbourhood or at a PA session in their local communitySupervised exercise frequency of once per week remainsParticipants will enact action plans for PA outside of the REACT programme that were made during the transition phase and will be supported through group social/education meetings once a monthEncourage groups to self-organise their own social interaction beyond the scope of the study and to consider doing activities togetherParticipants will be informed about local opportunities for PA in their communityTo support the need for detailed information and clarity about the details of a successful programme we have provided a detailed account of how the REACT exercise intervention was delivered in a comprehensive 