Effects and moderators of exercise on muscle strength, muscle function and aerobic fitness in patients with cancer: A meta-analysis of individual patient data

Objective: To optimally target exerciseinterventions for patients with cancer, it is important to identify which patients benefit from which interventions. Design: We conducted an individual patient data meta-analysis to investigate demographic, clinical, intervention-related and exercise-related moderators of exerciseintervention effects on physical fitness in patients with cancer. Data sources: We identified relevant studies via systematic searches in electronic databases (PubMed, Embase, PsycINFO and CINAHL). Eligibility criteria: We analysed data from 28 randomised controlled trials investigating the effects of exerciseon upper body muscle strength (UBMS) and lower body muscle strength (LBMS), lower body muscle function (LBMF) and aerobic fitness in adult patients with cancer. Results: Exercisesignificantly improved UBMS (β=0.20, 95% Confidence Interval (CI) 0.14 to 0.26), LBMS (β=0.29, 95% CI 0.23 to 0.35), LBMF (β=0.16, 95% CI 0.08 to 0.24) and aerobic fitness (β=0.28, 95% CI 0.23 to 0.34), with larger effects for supervised interventions. Exerciseeffects on UBMS were larger during treatment, when supervised interventions included ≥3 sessions per week, when resistance exerciseswere included and when session duration was >60 min. Exerciseeffects on LBMS were larger for patients who were living alone, for supervised interventions including resistance exerciseand when session duration was >60 min. Exerciseeffects on aerobic fitness were larger for younger patients and when supervised interventions included aerobic exercise. Conclusion: Exerciseinterventions during and following cancer treatment had small effects on UBMS, LBMS, LBMF and aerobic fitness. Demographic, intervention-related and exercise-related characteristics including age, marital status, intervention timing, delivery mode and frequency and type and time of exercisesessions moderated the exerciseeffect on UBMS, LBMS and aerobic fitness.