Does timing of exercise really matter for people with cancer? A systematic review and meta-analysis.

To determine the effect of earlier vs. later initiation of exercise rehabilitation for people with cancer on physical, psychosocial and health service outcomes.

Electronic databases CINAHL, Embase, MEDLINE and PubMed were searched from the earliest available date to March 2024. Randomised controlled trials that enrolled adults and/or children with a cancer diagnosis and compared groups receiving exercise rehabilitation at different times were included. The primary outcome of interest was physical activity. Other outcomes included patient health outcomes (e.g. cardiorespiratory fitness, walking capacity, fatigue, quality of life) and health service outcomes (e.g. hospital length of stay, readmissions, costs). Outcome data were extracted, and the methodological quality assessed using PEDro. Clinically homogenous data were combined in meta-analyses; overall quality of evidence was assessed using the Grading of Recommendations, Assessment, Development, and Evaluations approach.

Fifteen trials were included. Trials included participants (n=1,338) most commonly with breast (n=6), colorectal (n=3) and haematological (n=3) cancers. There was low to moderate certainty evidence demonstrating physical activity (SMD –0.03, 95% CI –0.60 to 0.54), fitness (SMD 0.17, 95% CI –0.14 to 0.48), walking capacity (SMD 0.78, 95% CI –0.6 to 0.54), fatigue (SMD –0.11, 95% CI –0.55 to 0.33) and quality of life (SMD 0.22, 95% CI –0.14 to 0.58) improved a similar amount regardless of exercise timing. Limited data were available for health service outcomes with no difference in hospital length of stay (MD 0 days, 95% CI -0.9 to 0.9).

People with cancer may achieve similar health benefits when exercise rehabilitation is initiated at any time following diagnosis. More research is needed to evaluate the effect of exercise timing on health service outcomes. Evaluating adherence to exercise may be important to identify key moments to provide exercise rehabilitation following a cancer diagnosis. 

Results of this review support the provision of flexible timing in relation to exercise rehabilitation for people with cancer. Individualising and optimising patient engagement and access to exercise rehabilitation along the cancer care continuum may be more important, rather than basing design of services on an assumption that ‘earlier is better’. Understanding the impact of timing of rehabilitation may guide health organisations to refine exercise rehabilitation service allocation.