Cancer Fatigue and the Exercise Connection
by Antoinette P. Sander, DPT, MS, CLT-LANA
Cancer fatigue is defined as a distressing, persistent, subjective sense of tiredness or exhaustion related to cancer or cancer treatment that is not proportional to recent activity and interferes with usual functioning. It affects most people with cancer during radiation and/or chemotherapy treatment, as well as months or years beyond treatment, and affects quality of life.
Many scales have been developed to measure components of cancer fatigue such as severity, frequency, and impact on function or cognitive abilities. A simple measurement is to rate fatigue experienced on a scale of 0 to 10, with 0 being no fatigue and 10 being the worst fatigue imagined.
There are several proposed causes of cancer fatigue. Primary factors are pain, anxiety, depression, sleep disturbance, poor nutrition, low blood counts, comorbidities such as cardiac or renal dysfunction, and decreased activity and physical fitness. A decrease in physical activity, which often accompanies cancer treatment, can create a loss of muscle mass and a reduction in cardiac output and respiratory capacity. These changes precipitate a deconditioning cycle where greater effort and energy are required to perform normal activities of daily living, which leads to fatigue and a further decrease in activity.
There is strong evidence that physical exercise can break the deconditioning cycle and reduce the symptoms of cancer-related fatigue. Physical exercise has been recommended during and following cancer treatment to decrease the loss in physical performance and increase functional capacity. In fact, when basic activities of daily living are difficult to perform, simply doing them can be exercise. These beginning activities could be bathing, dressing, making basic meals, and walking within the house. When basic activities become easy, more advanced functional activities like sweeping floors, vacuuming, mopping, washing the car, and mowing the lawn can be added.
Moderate intensity aerobic exercise is very effective in reducing symptoms of fatigue.
The first goal is to become more active, and then the intensity of the activity or exercise can be considered. Repetitions of everyday movements like standing up from a chair, reaching overhead, bending knees in a partial squat, and going up and down stairs can be an effective beginning exercise. In the early phases of the program, the goal is to be continuously active for 10-minute sessions three times a day, with a gradual increase to 30 consecutive minutes of activity at least five days a week.
Moderate intensity aerobic exercise is very effective in reducing symptoms of fatigue during and following cancer treatment. Walking, cycling, swimming, and elliptical training are examples of aerobic exercise that can be done individually or in groups. The intensity of the exercise can be monitored by using the Rate of Perceived Exertion, which is a self-assessment of how hard an individual is working during exercise. The RPE scale assigns number values to exercise intensity from “very, very light (7)” to “very, very hard (19).” Moderate exercise intensity has an RPE of 12 to 13 and is rated as “somewhat hard.” Walking at a brisk pace (3 to 4 miles an hour) is considered moderate intensity. This has been described as exercising hard enough that an individual can talk but cannot sing. Aerobic exercise needs to include warm up, training, and cool down phases. The warm up and cool down are typically the training activity at a slower pace.
A physician’s clearance should be obtained to progress exercise beyond a moderate intensity or if cardiac, respiratory, diabetic, musculoskeletal, or neurological problems are present. Exercise should be cautiously prescribed in the presence of bony metastasis, immunosuppression, low platelet counts, anemia, neutropenia, fever, or other treatment complications. A physical therapist can help determine the intensity, frequency, and duration of the exercise program and can help to develop and monitor a program tailored to the person’s age, gender, type of cancer, treatment, and physical fitness level.
Cancer fatigue is now recognized, evaluated, monitored, and treated both during and following cancer treatment. Exercise is a safe and effective intervention that has improved symptoms of fatigue in cancer survivors. Exercise has the added benefit of being under the control of the cancer survivor. The decision to exercise is individual, and the results can improve quality of life.
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Dr. Antoinette Sander is an assistant professor of clinical physical therapy in the department of Physical Therapy and Human Movement Sciences at Northwestern University Feinberg School of Medicine in Chicago, IL. She is also a physical therapist and a 14-year breast cancer survivor.
This article was originally published in Coping® with Cancer magazine, November/December 2007.