Context: Exercise-induced improvements in cancer-related fatigue may be moderated differentially
in patients during and following treatment. These effects have not been reviewed systematically. In
accordance with PRISMA guidelines, the population effect size for exercise training on cancerrelated
fatigue during and following treatment was estimated and the extent to which the effect is
differentiated across the time course of treatment and recovery was determined.
Evidence acquisition: Articles published before August 2011 were retrieved using Google
Scholar, MEDLINE, PsycINFO, PubMed, and Web of Science databases. Seventy studies involving
4881 cancer patients during or following treatment were selected. Articles included a cancer-related
fatigue outcome measured at baseline and post-intervention and randomized allocation to exercise
or non-exercise comparison. From August to October 2011, Hedges’ d effect sizes were computed,
study quality was evaluated, and random effects models were used to estimate sampling error and
population variance.
Evidence synthesis: Exercise signifıcantly reduced cancer-related fatigue by a mean effect (95%
CI) of 0.32 (0.21, 0.43) and 0.38 (0.21, 0.54) during and following cancer treatment, respectively.
During treatment, patients with lower baseline fatigue scores and higher exercise adherence realized
the largest improvements. Following treatment, improvements were largest for trials with longer
durations between treatment completion and exercise initiation, trials with shorter exercise program
lengths, and trials using wait-list comparisons.
Conclusions: Exercise reduces cancer-related fatigue among patients during and following cancer
treatment. These effects are moderated differentially over the time course of treatment and recovery.
Exercise has a palliative effect in patients during treatment and a recuperative effect post-treatment.