Background Multiple studies have shown that physical activity improves cancer survivorship, by decreasing risk of second primary cancers and chronic conditions. However, cancer survivor physical activity levels remain low. General practice presents more opportunities for lifestyle interventions, such as increasing physical activity. We conducted a realist review of physical activity interventions relevant to general practice.

Methods A total of 9728 studies were obtained from a systematic search of the CINAHL, Embase, PsycINFO, PubMed, and SPORTDiscus databases from the inception of the electronic database to 21 June 2024. We focussed on intervention studies that improved physical activity among cancer survivors and were relevant to general practice. Data extraction focussed on: what makes physical activity interventions effective for cancer survivors (what works) and what factors promote physical activity for cancer survivors (for whom it works).

Results Thirty-seven studies were used to generate themes on the components of physical activity interventions that are likely to work and for whom; these studies facilitated goal setting, action planning, self-monitoring, social support, and shaping of knowledge; through delivering tailored motivational support, evoking a teachable moment, and promoting the use of self-monitoring tools. Interventions that were cost-effective and easily implementable improved sustainability, deployability, and uptake by cancer survivors. Cancer survivor psychological and physical factors, such as baseline motivational levels and post-treatment symptoms, influenced the uptake of physical activity interventions.

Conclusion Our realist review has highlighted opportunities for general practices to promote physical activity among cancer survivors through collaborative goal setting, action planning, self-monitoring, social support, and shaping of knowledge.