Physical fitness can be of benefit during and after cancer treatment and a lack of exercise has been linked with the recurrence of forms of the disease.
Dr Julie Broderick of the Health Research Board objectively measured physical activity and fitness levels in a group of 100 cancer patients in Ireland.
She found fitness levels low at the time of diagnosis. "The fitness levels were much lower than predicted on a scale used by oncologists," says Dr Broderick, a research fellow at the Department of Physiotherapy in Trinity College Dublin.
She checked the patients to see if they had increased their levels of exercise after undergoing chemotherapy treatment.
The findings were not reassuring when she followed up with 29 patients for a year after treatment for breast or colon cancer.
"Physical activity stayed low and didn't improve over that year -- even though these survivors were finished their chemo, they hadn't picked up, they remained very inactive," she revealed.
In order to help the patients, Dr Broderick ran an eight-week exercise programme, where 23 cancer survivors who had finished chemo came to the hospital to participate in exercise classes.
Compared to patients who did not take part in the classes, the participants did not show increases in physical fitness, but they did find improvements in their quality of life.
The findings should help to increase awareness of the importance of physical activity during the cancer journey, according to Dr Broderick.
Other studies show that after a cancer diagnosis, people slow down. Stress, depression, and feeling sick or fatigued from cancer or its treatment all tend to make people less active.
It's different for every patient so it is wise to talk to your doctor before embarking on a moderate of vigorous exercise programme.
How far should a cancer patient push themselves?
As a general guideline, the advice is to take 30 to 60 minutes of moderate to vigorous exercise, at least five days a week.
If you've already been active keep it up, but if exercising is new to you, start slowly.
* If you're experiencing extreme fatigue, anaemia or a lack of muscle coordination (ataxia), don't exercise.
* If your immune system is compromised and your white blood cell count is low avoid busy exercise areas like gyms until your cell count is at a safe level.
* If you have pain or numbness from peripheral nerve damage or tingling in your hands or feet from chemotherapy, make sure you take precautions to reduce your risk of falling or injuring yourself.
* If you have any shortness of breath, pain, or tightness in your chest, stop exercising immediately.
* Speak to your doctor and try to work out an exercise programme that is right for you.