Systematic review of sleep disorders in cancer patients: can the prevalence of sleep disorders be ascertained?
CONTEXT Although numerous studies of the efficacy of exercise are reported, few studies have evaluated changes in characteristics of exercise dose in women with cancer both during and after cancer treatment. OBJECTIVES To describe the characteristics of exercise dose (i.e., frequency, duration, and intensity) and evaluate for differences in symptom severity (i.e., fatigue, sleep disturbance, depression, and pain) between women who did and did not exercise during and after cancer treatment. METHODS In a sample of 119 women, two groups were classified: exercisers and nonexercisers. Exercisers were defined as women who met specific criteria for frequency (three times per week), duration (20 minutes/session), intensity (moderate), and mode (aerobic). Nonexercisers were defined as women who did not meet all these criteria. Evaluation of exercise dose was completed at baseline (T1: the week before chemotherapy cycle 2), at the end of cancer treatment (T2), and at the end of the study (T3: approximately one year after the T1 assessment) using self-report exercise questionnaires. RESULTS Approximately 50% of the participants exercised during treatment and 70% exercised after treatment. At T1, exercisers had lower total fatigue, lower behavioral and sensory subscale fatigue scores, and lower depression scores (P = 0.038) than nonexercisers. No significant differences in sleep disturbance or pain were found between groups. At T2, exercisers had lower cognitive/mood subscale fatigue and depression scores than nonexercisers (P = 0.047). At T3, no significant differences were found between groups in any symptom severity scores. CONCLUSION Both during and after cancer treatment, achieving or maintaining exercise guideline levels were met by most patients. Further study is needed to examine the link between exercise dose and symptom severity.