Prehabilitation and rehabilitation will be essential services in an ageing population to support patients with cancer to live well through their life spans. Active Together is a novel evidence-based service embedded within existing healthcare pathways in an innovative collaboration between health, academic, and charity organisations. Designed to improve outcomes for cancer patients and reduce the demand on healthcare resources, it offers physical, nutritional, and psychological prehabilitation and rehabilitation support to patients undergoing cancer treatment. The service is underpinned by behaviour change theories and an individualised and personalised approach to care, addressing the health inequalities that might come about through age, poverty, ethnicity, or culture. Meeting the challenge of delivering high-quality services across multiple stakeholders, while addressing the complexity of patient need, has required skilled leadership, flexibility, and innovation. To support patients equally, regardless of geography or demographics, future services will need to be scaled regionally and be available in locations amenable to the populations they serve. To deliver these services across wide geographic regions, involving multiple providers and complex patient pathways, will require a systems approach. This means embracing and addressing the complexity of the contexts within which these services are delivered, to ensure efficient, high-quality provision of care, while supporting staff well-being and meeting the needs of patients.