There is a high prevalence of inactive adults in the United Kingdom (UK), many of whom suffer from conditions such as diabetes, cardiovascular disease, and poor mental health. These problems often co-exist more frequently in areas of higher socio-economic deprivation. There is an ongoing need to test the effectiveness, acceptability, and sustainability of community physical activity interventions. The Active Herts programme is a community physical activity programme aimed at inactive adults aged 16 and over who have one or more risk factors for cardiovascular disease (CVD) and/or a mild to moderate mental health condition. The programme uses the latest evidence-based behaviour change techniques to target physical activity, wellbeing, and key drivers of behaviour from the COM-B ('Capability', 'Opportunity', 'Motivation' and 'Behaviour') model of behaviour change.

This evaluation will follow a mixed-methods longitudinal (baseline, and 3, 6 and 12 month follow-ups) pragmatic observational design. Two types of programme are being delivered, each in a different area. In one, group participants will receive a behaviour change technique booklet, consultations (baseline, and optional at 3, 6, and 12 months), a booster phone call (week 2), motivational text messages (weeks 3, 6, and 12), and signposting to 12 weeks of exercise classes. In the other 'enhanced delivery' group, participants will receive the same but the 12 weeks of exercise will be free and tailored to their needs, and there will be optional exercise 'buddies' available. An outcome evaluation will assess changes in physical activity as the primary outcome, and sporting participation, sitting, wellbeing, psychological capability, and reflective motivation as secondary outcomes. A process evaluation will use both one-to-one interviews and focus groups to explore the views of stakeholders, delivery staff, and participants over three phases (set-up, deviations in the delivery of the intervention, and looking back over the intervention). Economic evaluation will examine the costs of the Active Herts programme against the benefits gained in terms of reduced risk of morbidity from a range of chronic conditions.

This study will measure key drivers of physical activity using up to date behaviour change theory, allowing evaluation of not only whether physical activity has increased but also why. The research will inform the future development of a scalable intervention that can be more robustly tested in a randomised controlled trial.

Inclusion Criteria:

• inactive adults and do less than 30mins of physical activity per week
• aged 16 or over
• resident of Hertfordshire boroughs, including Broxbourne, Hertsmere, Stevenage or Watford

Referred patients and clients may also have:

• a long term medical condition such as type 2 diabetes, hypertension, high cholesterol etc.
• a mild to moderate mental health condition such as anxiety, depression or stress
• a history or family history of heart disease

Exclusion Criteria:

• participants not able to give informed consent

Participants will live in one of four Hertfordshire districts (Broxbourne, Stevenage, Hertsmere, and Watford), United Kingdom. The four districts contain the highest number of deprived Lower Super Output Areas (LSOA) in Hertfordshire and are in the five highest rates of under 75 mortality rate from CVD (2-3%), adult obesity (8-10%), and diabetes (4-6%). A life expectancy gap of 6-9.6 years exists between the most and least deprived areas across these districts. Less than 50% of this population participate in 30 minutes of physical activity once per week.