Objective To synthesise qualitative literature on (1) the perceptions of patients with cancer of participating in an exercise intervention while undergoing chemotherapy and (2) to inform and guide professionals in oncology and haematology practice.

Design A qualitative meta-synthesis based on Noblit and Hare’s seven-step meta-ethnography.

Data sources Six electronic databases: Cochrane Central Register of Controlled Trials (CENTRAL), CINAHL, EMBASE, PubMed, SCI-Expanded—SSCI and Scopus (final search June 2022) were used to identify qualitative literature containing individual or focus group interviews. The transparency of reporting for each study was assessed using the Consolidated criteria for Reporting Qualitative research checklist.

Results The search identified 5002 articles, 107 of which were selected for full-text review. Seventeen articles from five countries with patients undergoing chemotherapy during exercise interventions were included. Eleven articles were included in the meta-synthesis, which comprised 193 patients with various cancer diagnoses, disease stages, sexes and ages. Four main themes were identified: chemotherapy overpowers the body; exercise in battle with side effects; a break from gloomy thoughts; and a question of survivorship.

Conclusions and implications The meta-synthesis emphasised that patients with cancer undergoing chemotherapy and simultaneously participating in exercise interventions may experience momentary relief from overwhelming side effects, even though full bodily recovery may be perceived as a distant prospect. The synthesis offers a sparse empirical basis for gaining insight into what patients experience existentially following exercise interventions. It is up to patients to independently apply the transfer value of exercise to their own existential circumstances.