Courneya, K.S., Segal, R.J., Mackey, J.R., Gelmon, K., Friedenreich, C.M., Yasui, Y., . . . McKenzie, D.C. (2014). Effects of exercise dose and type on sleep quality in breast cancer patients receiving chemotherapy: A multicenter randomized trial. Breast Cancer Research and Treatment, 144, 361–369.

To compare the effects and doses of a three-arm exercise trial to improve sleep quality in patients with breast cancer receiving active chemotherapy

The three-group design of the CARE trial compared the standard dose of 25–30 minutes of aerobic exercise (STAN) to higher doses of activity that included 50–60 minutes of aerobic exercise (HIGH) and 50–60 minutes of combined-dose of aerobic and resistance exercise (aerobic and strength training three times per week) (COMB). COMB strength training was part of the 50–60 minute session and included two sets of 10–12 repetitions of nine different strength exercises at 60%–75% of the estimated one-repetition max (RM). All groups received three weekly treatments with outcomes measures to determine primary and secondary outcomes. Interventions continued for the duration of chemotherapy. Data were collected at baseline, midpoint 1, midpoint 2, and postintervention.

• N = 296
• MEAN AGE = > 18 years M = 50 (SD = 8.7 years)
• FEMALES: 100%
• KEY DISEASE CHARACTERISTICS: Patients with breast cancer receiving active chemotherapy
• OTHER KEY SAMPLE CHARACTERISTICS: English or French speaking; not pregnant; stages I–IIIc

• SITE: Multi-site    
• SETTING TYPE: Multiple settings    
• LOCATION: Canada

• PHASE OF CARE: Active antitumor treatment

Blinded, randomized, controlled trial

• Primary outcomes were measured using the Pittsburgh Sleep Quality Index (PSQI).
• Secondary outcomes for moderators for plausibility included clinical utility, support for previous research used, age, aerobic exercise guidelines, strength exercise guidelines, comorbidities, body mass index, aerobic fitness (treadmill and gas exchange), and medical moderators from records (stage, surgery, and chemotherapy).

296 patients completed the study with complete data. Baseline global sleep scores were M = 6.2 (SD = 4.1) with 52% of participants reporting poor sleep at baseline (PSQI > 5). The main effects of the study showed that the HIGH group had statistically better outcomes compared to the STAN group for primary sleep global scores (d = 0.22; p = 0.039), sleep quality (d = 0.26; p = 0.028), and sleep latency (d = 0.18; p = 0.049). The COMB group barely scored significantly higher than the STAN group for global sleep quality, sleep duration, and sleep efficiency (d = 0.24; p = 0.04)  and percent of poor sleepers (d = 0.20; p = 0.045). The HIGH group was statistically better than COMB for sleep latency only (d = 0.20; p = 0.04) . Significant moderators included surgery, baseline aerobic fitness, baseline aerobic exercise guidelines, baseline strength guidelines, and number of comorbid conditions. The effect size for the HIGH group compared to the STAN group was larger for global sleep quality for lumpectomy patients with no comorbid conditions, those meeting aerobic exercise guidelines, and those who were fitter at baseline. Scores in the COMB group were higher than those of the STAN group for lumpectomy patients meeting strength exercise guidelines. The overall effect for each arm was small.

Higher doses of exercise and the combination of exercise and strength training were associated with better overall sleep quality compared to the standard dose of 50–60 minutes of aerobic exercise. Different sleep components appeared to be most affected by the type of exercise intervention, and no single intervention impacted all the sleep components measured.

• Measurement validity/reliability questionable
• Findings not generalizable
• Intervention expensive, impractical, or training needs
• Other limitations/explanation: There were no noted statistics to compare the three intervention groups as reported in the manuscript, so it is unclear whether group differences were present. The findings of this study only are generalizable to breast cancer and cannot be generalized to other active patients with cancer. The intervention assumes that patients have access to exercise support and gyms with the COMB part of the intervention. This might not be realistic for some areas with rural populations. The PSQI was validated using all 19 items, but this study eliminated nine (sleep disturbance) questions without a validation of the questionnaire, thus reducing the overall validity and reliability of the findings that were based on the global sleep quality index.

Nurses often suggest maintaining activity during treatment, but there is little information about the effectiveness of this recommendation on sleep-wake disturbances. This study provided a large sample of patients with breast cancer that narrowed down the doses needed to affect sleep. The overall results of this study suggest that exercise can improve sleep during chemotherapy treatment. However, the limitations of this study need to be taken into consideration before recommending the actual interventions used.