Velthuis, M. J., Agasi-Idenburg, S. C., Aufdemkampe, G., & Wittink, H. M. (2010). The effect of physical exercise on cancer-related fatigue during cancer treatment: a meta-analysis of randomised controlled trials. Clinical Oncology (Royal College of Radiologists (Great Britain)), 22, 208–221.

To evaluate short- and long-term effects of different exercise parameters during adjuvant treatment on cancer-related fatigue.

Databases searched were CINAHL, EMBASE, MEDLINE, Scopus, PEDro, and Cochrane Library to 2008. Hand searching was performed using reference lists from articles obtained.

Search keywords were cancer (and related terms), chemotherapy, radiotherapy, hormone*, exercise, cycle, train*, walk, and fatigue.

Studies were included in the review if 

• They were randomized, controlled trials
• They studied effects of exercise on cancer-related fatigue in adults receiving adjuvant therapy
• There was overlap of 50% or more of the exercise intervention with the cancer treatment period
• The study compared exercise with a no exercise usual care group
• Patient-reported fatigue was the outcome.

No exclusion criteria were specified.

Initally, 1,097 articles were identified. A final set of 18 articles met the inclusion criteria. The PEDro scale was used to rate the methodological quality of the research. Fifteen studies were considered to be of high quality, with a score 4 or greater (range 2–8).

• The final sample of 18 studies involved 1,109 patients.
• Study sample sizes ranged from 14 to 174 patients.
• Twelve of the 18 studies were performed in patients with breast cancer.

Overall Findings in Breast Cancer

• Pooled results in patients with breast cancer (n = 654) showed a small significant reduction in fatigue with exercise (standardized mean difference [SMD] = 0.22; 95% confidence interval [CI] [0.06, 0.37]; Z = 2.46; p = 0.01).

Home-Based Exercise

Exercise was home-based and self-monitored in seven studies. Interventions consisted of walking for 10 to 45 minutes per week and for three to six times per week. In one study, the participants also performed resistance exercises. Cancer treatments and timing of the programs varied. Adherence ranged from 70% to 100%.

• Pooled results of 2 high-quality studies (n = 128) showed a small nonsignificant reduction in fatigue (SMD = 0.10; 95% CI [-0.25, 0.45]).

Supervised Exercise Programs

Supervised programs were used in five studies. Three involved aerobic exercises, and the others included groups with stretching and/or resistance exercises. Most were performed for 10 to 30 minutes three times per week. Programs were completed by 39% to 100% of partcipants.

• Pooled analysis of three high-quality studies (n = 340) showed a medium significant reduction in fatigue with exercise (SMD = 0.30; 95% CI [0.09, 0.51]).

Overall Findings in Prostate Cancer

Four studies were performed in patients with prostate cancer; three were supervised and one was home-based.

• Pooled results in these five studies showed a medium significant reduction in fatigue with exercise (SMD = 0.32; 95% CI [0.05, 0.59]).
• Subgroup analysis of home-based and supervised programs showed small nonsignificant effects, with these approaches analyzed individually.

Findings in Multiple Myeloma and Acute Myeloid Leukemia

One study was performed in each of these patient groups. One was of low quality. Both had nonsignificant reductions in fatigue.

Only short-term effects could be analyzed because only one study described any longer-term effects of physical exercise. No significant adverse effects overall were seen. Supervised aerobic exercise programs were more effective in reducing fatigue than home-based programs. There were significant positive effects during breast cancer treatment, with small to moderate effect sizes. The most effective frequency intensity or duration of exercise could not be determined. Reported adherence to the exercise program varied widely.

• There was an overall beneficial effect of exercise in patients with prostate cancer when all findings were pooled; however, the effectiveness of home-based and supervised programs could not be demonstrated separately.
• The limited number of studies and available data in this area may have influenced these results.
• The clinical relevance of findings could not be determined due to the wide range of measurement instruments used in the research and the lack of associated data that establish clinically important differences.

Findings showed that exercise had at least a small beneficial effect in reducing fatigue for patients during adjuvant treatment. Supervised programs may be more effective than self-managed home-based programs. More research on the effects of resistance exercise, home-based exercise, and most effective exercise parameters are needed. Longer-term outcomes and patient adherence need to be examined further. Research on the effects of exercise in other patient types is also needed.