Table 1 Checklist considerations when characterizing implementation setting parameters (Step 1)

Intervention population (Individual level)

1. Who will access the intervention? What is the size of the target population? Are there participation eligibility criteria (i.e. age)? Are there subgroups that experience disparities in physical activity?

2. How will the target population access/be recruited into the intervention? What will motivate or incentivize them to take part? How will you ensure equity of access for disadvantaged subgroups?

3. How will retention be supported and monitored? How will you ensure those who may be at higher risk of attrition will be retained and how will this be monitored?

Implementers (Provider level)

4. Who will deliver the intervention? How many implementers will be required? Are there eligibility criteria to deliver the intervention (i.e. level of skill, knowledge, education)?

5. How will implementers be identified/engaged and trained? What will motivate or incentivize them to implement the intervention? How will you facilitate engagement with disadvantaged groups?

6. How will implementers be supported (i.e. ongoing training, performance feedback, champions) to sustain intervention fidelity and delivery? How will you prepare for sustainability in lower-resourced settings?

Delivery setting/org. (Organizational level)

7. What is the target delivery setting(s) (i.e. setting, size) and are there eligibility criteria for adoption (i.e. possess certain resources)? How will you engage settings that provide services to disadvantaged subgroups?

8. How will target delivery settings be identified and be made aware of the intervention? What will motivate or incentivize the setting to adopt and implement the intervention?

9. Who will take ownership of the intervention and how will adoption, delivery, impact, and sustainability be monitored? How will start-up and ongoing costs be considered when planning for sustainability and implementation at scale?

Environment/ context (Community/ systems level)

10. What are the key characteristics of the target community (i.e. built environment infrastructure, low-high income)? How will you engage communities with disadvantaged subgroups?

11. How will characteristics of the community (i.e. funding and political climate, readiness for implementation) influence dissemination, implementation and scale-up? How will community accountability for implementation be generated and assessed?

12. Who at the community/systems level will be responsible for the intervention? Are there individual or organizational champions for intervention implementation that could help to plan for sustainability?

Intervention factors: (All levels)

13. What is the intervention design (i.e. strategies, underlying principles, delivery format, duration, resources required)? What are the core and adaptable elements (i.e. flexibility)? Which elements may/may not be scalable? How simple/complex is the design and what relative advantage does the intervention provide?

14. How will the intervention and plans for implementation, be developed so they align with organizational missions, values and infrastructure (i.e. size, resource availability)? How will the intervention integrate into existing individual and organizational practices (i.e. setting compatibility)?

15. How will the intervention and associated costs and resources for delivery (i.e. materials) be sustainably funded? How will intervention implementation processes (i.e. setting/staff training) be integrated into organizational policies and job descriptions? How will implementation capacity be developed and sustained at scale?