Grading the evidence on the effects of exercise interventions in children and adolescents during and beyond cancer treatment: an umbrella review of systematic reviews with meta-analyses.

Abstract

To synthesise the evidence on the effects of exercise interventions in children and adolescents during and beyond cancer treatment, and to evaluate the methodological quality and certainty of this evidence. Umbrella review of systematic reviews with meta-analyses. PubMed, Web of Science, Scopus, SPORTDiscus and CINAHL were searched from inception to January 2026. Systematic reviews with meta-analysis of controlled trials (randomised or non-randomised) evaluating exercise interventions in children and adolescents (≤19 years) during and beyond cancer treatment. Reviews without quantitative synthesis, those including only observational studies, or interventions where the isolated effect of exercise could not be determined were excluded. 19 systematic reviews with meta-analyses, including 53 primary studies (n=2361 participants), were identified, yielding 80 effect estimates. Attending to the most comprehensive meta-analyses, exercise induced significant benefits on cardiorespiratory fitness (mean difference (MD) 6.92% (95% CI 1.01% to 12.82%)), cognitive function (standardised mean difference (SMD) 0.26 (95% CI 0.08 to 0.44)) and cognitive performance (SMD 0.41 (95% CI 0.17 to 0.65)), with moderate certainty of evidence. Exercise also induced significant benefits on muscle strength (SMD 0.81 (95% CI 0.05 to 1.57)), functional mobility (MD -1.17 s (95% CI -1.86 to -0.49)) and cancer-related fatigue (SMD -0.62 (95% CI -1.21 to -0.03)), although the certainty was low or very low. These effects were observed across meta-analyses focused exclusively on studies conducted during treatment (n=26), after treatment (n=3) or both (n=51). In contrast, no significant effects of exercise were observed for depression, bone mineral density, health-related quality of life, anthropometry or other clinical outcomes (such as mortality, relapse risk and withdrawal rates). Exercise appears to be a beneficial intervention in childhood cancer for improving some physical, cognitive and psychosocial outcomes. However, more high-quality research is warranted to strengthen clinical recommendations and inform personalised exercise prescriptions, given that the certainty of evidence remains variable and overall low across outcomes. CRD420251031412.