Fitness Is Important For The Road To Recovery
By Dr Jason Chia
Sports Physician, Sports Medicine Centre
Changi General Hospital

Exercise has been shown to improve the quality of life for cancer survivors. The benefits go beyond the physical. It improves overall function and brings with it the psychological benefits. Just like any healthy person, exercise helps to decrease the risk of developing chronic diseases such as diabetes and hypertension.

For a cancer survivor, there are other benefits as well. Exercise can help to ameliorate some of the effects due to cancer or its treatment. For example, cancer can lead to muscle wasting. This may be caused by a loss of appetite due to chemotherapy. For some, prolonged bed rest can lead to loss of cardiovascular fitness. Conversely, some hormonal agents used in chemotherapy can result in excessive weight gain.

What are some of the concerns of exercise?

a. potential immunosuppression through vigorous exercise
b. bone fractures due to decreased bone strength
c. exacerbation of cardiotoxicity caused by chemotherapy
d. aggravation of pain

However, studies have shown that moderate exercise (with precautions) have an overall beneficial effect for the survivor. The mode of exercise as well as intensity has to be tailored to the individual, and will vary with the state of health at the point in time, including the stage of the disease, ongoing treatment, side effects of treatment and other concurrent illnesses.

The general recommendations for cancer survivors are similar to those of healthy individuals with 3-5 sessions of exercise per week for 20-30 minutes per session. More frequent sessions with shorter bouts of exercise may be preferable for those who are unconditioned. The exercises of choice are aerobics, walking and cycling. High impact sports and contact sports should be avoided for those with cancer involving the bone disease. Also, the mode of exercise may need to be modified according to the limitation of joint movement due to surgery for e.g. breast cancer with extensive lymph node resection, and oedema of the arm may find upper limb exercises uncomfortable.

Strength training 1-2 sessions per week can be used as an adjunct to reverse muscle wasting.

The intensity of the exercise should be 60-80% of your maximum heart rate (this is estimated by 220 – age). High intensity exercise should be avoided during treatment because of potential immunosuppression but is not contraindicated in cancer survivors.

There are certain precautions that one should adhere to. For instance, those with fever and severe anemia should avoid vigorous exercises. Contact and high impact sports should be avoided for those with low platelet counts. Shortness of breath e.g. after resection of part of the lung for cancer can limit oxygen uptake. Thus the intensity of exercise should be limited by the degree of breathlessness.

The choice of sports, while largely based on individual preference, is also influenced by the state of health. For example, when starting from a low level of fitness, it is necessary to begin with lower intensity exercises e.g. brisk walking, to train up cardiovascular fitness before progressing to more demanding exercises such as soccer. This is especially so if there has been a significant loss of weight e.g. > 35%, of initial body weight leading to loss of muscle mass.

Sports that require much coordination and balance, e.g. basketball, may not be suitable if there is dizziness or numbness, which sometimes occurs as a result of chemotherapy. In addition, certain drugs can be toxic to the heart so it is necessary to consult with your oncologist before starting on vigorous exercise.

Hormonal therapy, which is used to fight cancer cells, can sometimes lead to weight gain with the loss of muscle mass. To regain a healthy weight, it is necessary to ensure that a deficit in calories (about 500kcal per day) be created through a combination of decreased intake and increased physical activity. The caloric deficit should not be too big as rapid weight gain can lead to further loss of muscle mass.

While the exercises should largely be aerobic in nature (accumulated total of 200-300 minutes per week), strength training may also be added which, in combination with adequate protein intake, serves to maintain muscle mass during the weight loss stage. Bear in mind that the capacity to exercise may initially be low due to a lack of cardiovascular fitness and muscle-wasting, therefore the initial exercise can be low in intensity. The exercise may be accumulated in short bouts, several times each day, until fitness improves, at which point longer sessions may be scheduled.

*Immunosuppression - Suppression of the body's immune system and its ability to fight infections or disease. It may be deliberately induced with drugs, as in preparation for bone marrow or other organ transplantation to prevent rejection of the donor tissue. It may also result from certain diseases such as AIDS or lymphoma or from anticancer drugs.