Hayward, Reid

Committee Member

Hydock, David

Committee Member

Haughian, James

Committee Member

Pullen, Nicholas


College of Natural Health Sciences; School of Sport & Exercise Science, Exercise Physiology


University of Northern Colorado

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Place of Publication

Greeley, (Colo.)


University of Northern Colorado

Date Created



118 pages

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Born digital


Poor sleep quality is a common side effect among cancer survivors, which could lead to a decrease in quality of life and worsen a variety of clinical outcomes for cancer patients including risk of infection and cancer recurrence. The detrimental effects of poor sleep quality are correlated with a disruption in circadian rhythm, which is a vital component of essential physiological processes. Exercise could improve sleep quality and circadian rhythm in an apparently healthy population but evidence was lacking in the cancer population. The purpose of this study, therefore, was to explore the effects of individualized, prescribed, supervised exercise on sleep quality in cancer patients by using objective measures of sleep efficiency, total sleep time, and duration of time spent in each stage of sleep. A secondary purpose was to determine if the potential changes in sleep quality were accompanied by changes in markers of peripheral circadian rhythm. Cancer survivors currently receiving chemotherapy and/or radiation therapy were recruited for the study. Nineteen participants were divided into an exercise group (n=12) and a sedentary control group (n=7). The exercise group completed a 12-week exercise intervention, whereas the control group continued usual care for 12 weeks. Each participant wore a sleep tracking device throughout the intervention. Blood samples were collected at 6:00am, 12:00pm, 6:00pm, and 12:00am on a single day before and after the 12-week intervention to measure circadian gene expression (Per1, Per2, Per3, Cry1, Cry2, Clock, Bmal1). Exercise resulted in a significant increase in total sleep time hours (Pre: 6.23 ± 1.25, Post: 6.80 ± 0.95, p<.05) and light sleep time (Pre: 3.63 ± 0.69, Post: 4.17 ± 0.68, p < .001). There was no significant change in all other sleep variables. In the control group, mean values were consistently lower for total sleep time (Pre: 6.64 ± 0.91, Post: 6.35 ± 0.76), REM Sleep (Pre: 1.86 ± 0.37, Post: 1.53 ± 0.30), and light sleep time (Pre: 3.68 ± 0.69, Post: 3.30 ± 0.38) after the 12-week intervention period. In addition, exercise had no significant effect on peripheral circadian rhythm as evidenced by a lack of change in relative expression of core circadian clock genes. Exercise resulted in an increase in multiple parameters of sleep quality. Control participants did not see an improvement in any parameters of sleep quality and, in fact, saw a trending decline in total sleep time, REM sleep, and light sleep. Exercise might be a promising intervention to alleviate sleep disturbances that often results from cancer treatments but these beneficial effects of exercise did not coincide with a normalization of peripheral circadian rhythm in cancer patients undergoing treatment.

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