Lion Hearts: applying implementation mapping to plan the delivery of a family-based physical activity intervention in community CrossFit affiliates.

Implementation Mapping was applied through a co-design process with seven CrossFit affiliate owner-coaches to plan delivery of the Lion Hearts family-based physical activity intervention.

• Lion Hearts targets cardiovascular health in mothers and children aged 3-6 years.
• All five iterative Implementation Mapping tasks were completed: needs/assets assessment and identification of adopters and implementers; specification of outcomes, performance objectives, determinants, and change objectives; selection of theoretical change methods and strategies; production of protocols and materials; and development of an evaluation plan.
• Two 60-minute co-design sessions were conducted approximately eight weeks apart.

Data from the co-design sessions were analyzed using rapid qualitative analysis and integrated with behavioral theory and implementation science frameworks.

• Audio recordings were transcribed verbatim.
• Three researchers reviewed and coded both transcripts using structured matrices, supplemented by facilitator notes.
• The first session elicited barriers and facilitators to adoption and delivery within affiliate settings.

Stakeholders identified multiple implementation determinants for delivering Lion Hearts in CrossFit affiliates.

• Determinants included coach knowledge and self-efficacy, participant engagement and competing demands, class structure and flow, scheduling, staffing, equipment availability, and compatibility with affiliate workflows.
• These were identified through the co-design sessions with the seven owner-coaches.

Implementation strategies and delivery supports were developed that target affiliate owners and coaches.

• Products included coach training resources, structured session templates, class-flow guidance, and fidelity-monitoring tools.
• The strategies were informed by the stakeholder-identified determinants and by theory-based change methods.

Performance objectives and an implementation logic model were developed to specify hypothesized pathways from determinants and strategies to implementation outcomes.

• The logic model links determinants and strategies to prospective implementation outcomes.
• It is intended to guide testing and refinement in the subsequent pilot.

A prospective implementation-evaluation plan was developed for the pilot to assess six implementation outcomes.

• Planned outcomes are reach, adoption, feasibility, acceptability, fidelity, and maintenance.
• The study is registered at ClinicalTrials.gov (NCT07147387).
• Implementation outcomes have not yet been evaluated.

The combination of Implementation Mapping and stakeholder co-design yielded a theory-informed, contextually responsive implementation package positioned for pilot testing in community fitness settings.

• The package comprises strategies, materials, and a prospective evaluation plan.
• The authors state the package is positioned for testing and refinement.