Cancer treatment and physical activity

Cancer is the name given to any one of a large number of diseases that develop when cells become abnormal and divide uncontrollably. These cells can destroy normal body tissue, produce harmful tumours and can spread throughout the body.

How physical activity can help

If you are being treated for cancer, physical activity can help to:

  • increase your energy levels
  • reduce anxiety
  • reduce nausea
  • improve your mood and self-esteem
  • reach and maintain a healthy weight
  • improve the quality of your sleep

After your treatment, physical activity can help prevent cancer coming back. It can also reduce the risk of developing other cancers or chronic illnesses such as heart disease and type 2 diabetes.

Regular physical activity can help reduce the risk of:

  • developing cancer of the bowel
  • breast cancer in women after menopause
  • endometrial cancer (cancer in the lining of the womb)


Check with your GP before you start becoming more active. Your GP can give you advice and support on becoming more active while managing your condition.

Exercise during chemotherapy or treatment for radiation

During chemotherapy or radiation treatment, try to be as active as possible. You may need to be less active for a time and build your activity levels more slowly.

Some chemotherapy or radiation treatment and their side effects can affect the type and amount of physical activity you can do. Be gentle with yourself and do what you can.

Severe anaemia

If you have severe anaemia, don’t start exercising until your red blood cell count returns to a safe level.

Impaired immune system

If you have a low white blood cell count, do not use public gyms, swimming pools and other public places until your cell count returns to a safe level.

Open wounds or radiation therapy

Avoid swimming pools if you have open wounds or you are having radiation therapy. The chlorine (a chemical used to clean the pools) may irritate your skin.

HSE exercise videos 

Try our exercise videos at home

Page last reviewed: 30 January 2019
Next review due: 30 January 2022