The Effects of Exercise on Fatigue in Cancer Patients Undergoing Chemotherapy

Abstract:  For those cancer patients who elect to receive chemotherapy, it appears that exercise can reduce the negative side effects of fatigue.  In one study, 61 women who had been newly diagnosed with breast cancer who engaged in a home exercise regime of low to moderate intensity reported significantly reduced levels of fatigue.  In a larger randomized controlled study, 291 patients of various ages and genders who performed a supervised exercise regime reported a moderate reduction in fatigue.  In a third study, advanced stage lung cancer patients reported an increase in emotional wellbeing and functional and physical capacity, but not a significant reduction in fatigue.  These findings indicate that further clinical trials on the effects of exercise on patients undergoing chemotherapy need to be conducted.

Tricia Lantzy

MSIS Candidate Spring 2013, School of Information

Graduate Research Assistant, Perry-Castañeda Library

University of Texas-Austin

tricialantzy@austin.utexas.edu

Glynn Harmon

Professor, School of Information

University of Texas-Austin

Ph.D., Information Science

Case Western Reserve University

gharmon@ischool.utexas.edu 

________________________________________________________________________________________

 

Introduction

Cancer is one of the top killers in the United States.  According to the most recent statistics, 25% of all deaths in the United States are caused by some form of cancer.  The lifetime probability of being diagnosed with cancer is 45% for men and 38% for women (1).  This is a staggering statistic and it reinforces the importance of research that seeks to reduce the occurrence of cancer and to reduce the pain and discomfort of cancer treatment once cancer occurs.  Chemotherapy is one of the most common treatment options for cancer patients, and the unpleasant side effects are well known to the general population.  It is used either alone or in conjunction with other treatments such as surgery or radiation therapy.  Unfortunately, fatigue is a major side effect experienced by chemotherapy patients.  According to Schwartz (2), “Cancer treatment-related fatigue is the most prevalent and disturbing side effect of treatment for the majority of cancer patients.  Fatigue leads to declines in emotional, psychosocial, and physical function.”

In order to diminish the burden of fatigue in cancer patients undergoing chemotherapy, researchers have begun to examine exercise as a possible solution.  Several studies conducted since 2000 have shown a significant decrease in fatigue experienced by these patients as a result of an exercise program.  There has yet to be consensus about the most effective type and duration of exercise program for cancer patients, but the evidence points distinctly to exercise as being a strong opponent to chemotherapy-related fatigue. 

Background

According to the American Cancer Society (3), there are many available treatment options for individuals diagnosed with cancer.  The treatment chosen by an individual and their doctor depends on several factors, such as the stage of the cancer and the preferences of the patient and doctor.  The most common treatments include surgery to remove the cancerous cells, chemotherapy or the use of strong drugs to treat the cancer, and radiation therapy or the use of high-energy particles to destroy cancerous cells.  Targeted therapy is a new form of treatment that attempts to identify and attack only cancerous cells (an effort to solve chemotherapy’s problem of killing healthy cells in addition to cancerous cells) and immunotherapy uses the body’s natural immune system to fight the cancer.  There are numerous other treatments for cancer, but for the sake of this article, we will only be examining chemotherapy.

Chemotherapy is the use of drugs to treat cancer.  There are over 100 different types of chemotherapy drugs on the market.  Sometimes more than one type of drug is prescribed, a method called combination chemotherapy.  In many cases, chemotherapy is used in conjunction with other methods of treatment such as surgery or radiation therapy.

The goal of chemotherapy is to kill the cancerous cells in the body; however, the drugs used can also harm healthy cells in the body.  It is possible that fatigue experienced during chemotherapy is a side effect of the body trying to repair its damaged cells.  In addition, it is also very likely that the cancer itself could be the cause of fatigue.  According to Mayo Clinic (4), some cancers release cytokines, proteins that are known to cause fatigue.

Despite different potential causes, the ability to reduce the symptom of fatigue would be a significant relief to cancer patients.  The following studies have explored exercise as an option for reducing fatigue in cancer patients undergoing chemotherapy.

Literature Review

Schwartz (2) employed an unsupervised, home-based exercise program for chemotherapy patients in order to observe the program’s effect on daily fatigue levels.  The subjects were women who had been newly diagnosed with breast cancer and of the 72 enrolled, 61 finished the program.  The subjects were able to choose the type of exercise they wanted to perform, which was usually of low to moderate intensity.  They would record their daily levels of fatigue as well as their exercise in journals.  The authors were concerned with how exercise affects feelings of fatigue in the short term, and on a day-by-day basis.

The study concludes that there was a significant decrease in levels of fatigue in response to 60 minutes of exercise.  This decrease lasted for about a day after the exercise was performed.  They also found that if exercise exceeded 60 minutes, fatigue began to increase.  Schwartz states, “The reason for this is unclear, perhaps prolonged exercise provokes muscular fatigue and the feelings of fatigue associated with changes in nutrition and hydration states that could increase the sensation of current level of fatigue.”  This is a valuable study because it begins to narrow down the duration of exercise that is beneficial to cancer patients.  The fact that the exercise was unsupervised yet subjects still had high completion rates is a hopeful result; it suggests recently diagnosed cancer patients would be able to participate in these types of physical activities and reap the benefits without the need for supervision or outside support (in terms of a physical therapist or personal trainer).

In 2009, a study by Adamsen et al. (5) assessed how an exercise routine of high intensity cardiovascular training in conjunction with resistance training would affect cancer patients undergoing chemotherapy.  This was a randomized controlled study and included 269 patients.  The exercise regime lasted for 6 weeks and was supervised by the researchers.  This study found not only that this type of exercise intervention reduced levels of fatigue, but it also improved aerobic capacity, emotional well-being, and muscular strength.  It is important to note that although the group that received the intervention had lower levels of fatigue in comparison with the control group, their fatigue levels were still higher than the general population.

This study is distinctive because of the inclusion of a wide range of diagnoses, ages, and stages of cancer.  Both men and women were represented in the study, and the number of participants is very high in comparison to the majority of case studies on exercise during chemotherapy treatment.  Although there were no significant changes reported in the Quality of Life measurement, the authors argue, “…a complete, partial, or periodic reduction in fatigue affected the patients’ daily lives (5).”  Based on the high participant number, this study is a strong argument for exercise as a means of reducing fatigue as well as for the incorporation of resistance training into the exercise program, which the Schwartz (2) study lacks.

A 2012 study by Quist et al. (6) looked specifically at the safety and feasibility of cancer patients undergoing an exercise regime while in the process of chemotherapy.  This study is interesting because it examined cancer patients with advanced stages of lung cancer, differentiating it from other studies that only include patients with early or intermediate stages of cancer.  This study did not produce a significant finding in levels of fatigue for individuals who undertook an exercise regime, but the subjects involved did report an increase in physical capacity, functional capacity, and emotional wellbeing.

The fact that this study was not able to show a statistically significant reduction in fatigue may indicate that exercise can reduce fatigue in chemotherapy patients who have early or intermediate stages of cancer.  That is not to say exercise is not important or worthwhile when individuals are diagnosed with advanced stages of cancer, as shown by the significant improvements in areas such as emotional wellbeing.

The researchers choose to implement a supervised exercise regime, claiming that, “Home training was not a valid option in this population since only 2 out of the 29 patients included in the intervention actually performed the home-based training (6).”  There seems to be evidence, based on these three case studies, that a home-based exercise program has potential to work for individuals with early or moderate forms of cancer, while it may be more difficult for individuals with advanced stages of cancer to comply with an exercise program at home.    

Discussion

The three case studies examined in this article are only a small fraction of the growing compilation of studies that test the relationship between exercise and fatigue for chemotherapy cancer patients.  Schwartz (2) demonstrates the effectiveness of exercise in reducing fatigue for recently diagnosed breast cancer patients.  Adamsen (5) also demonstrates a reduction in fatigue in response to an exercise program, but the program is composed of both cardiovascular training and resistance training.  Quist (6) demonstrates improvements in physical capacity, functional capacity, and emotional well-being, but not in fatigue.  This seems to be a result of the studies’ focus on patients with advanced stages of lung cancer.

Conclusion 

It is possible to conclude from this review that patients with early and intermediate phases of cancer who are receiving chemotherapy can reduce their symptoms of fatigue by taking part in low to moderate intensity exercise.  It also seems that these patients would have a relatively high success rate with home-based exercise programs.  Although these particular studies do not show a reduction in fatigue for patients with advanced stages of cancer, exercise is still beneficial in other ways, such as emotional wellbeing.  It is possible these patients might find it more difficult to stick to a home-based exercise routine due to the heavy burden of late stage cancer.  Therefore, a supervised routine might be more effective.  The results of these studies are promising enough to justify further clinical trial research on the effects of exercise on patients who receive chemotherapy.

References 

1. Siegel, R., D. Naishadham, and A Jemal. “Cancer statistics, 2012.” A Cancer
Journal for Clinicians 62 (2012): 10-29.

2. Schwartz, A, M Mori, R Gao, et al. “Exercise reduces daily fatigue in women with breast cancer receiving chemotherapy.” Journal of Medicine & Science in Sports & Exercise 33, no. 5 (2001): 718-723.

3. “Treatment Types.” American Cancer Society. Last modified 2012.
http://www.cancer.org/Treatment/TreatmentsandSideEffects/TreatmentTypes/index.

4. “Cancer fatigue: Why it occurs and how to cope.” Mayo Clinic. Last modified July
28, 2011. http://www.mayoclinic.com/health/cancer-fatigue/CA00032.

5. Adamsen, L , M Quist, C Anderson, et al. “Effect of a multimodal high intensity
exercise intervention in cancer patients undergoing chemotherapy:
randomised controlled trial.” British Medical Journal b3410 (2009): 339.

6. Quist, M, M Rorth, S Langer, et al. “Safety and feasibility of a
combined exercise intervention for inoperable lung cancer patients
undergoing chemotherapy: A pilot study.” Lung Cancer 75 (2012): 203-208.

7. Galvao, D A and R Newton. “Review of Exercise Intervention Studies in Cancer Patients.” Journal of Clinical Oncology 23, no. 4 (2005): 899-909.

  

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About CA Care

In obedience to God's will and counting on His mercies and blessings, and driven by the desire to care for one another, we seek to provide help, direction and relief to those who suffer from cancer.

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