A ground-breaking Glasgow study found women who exercised regularly during treatment for breast cancer had lower levels of depression five years later.
The research, carried out by Strathclyde University, is the first study into the long-term benefits of exercising during treatment.
More than 200 women took part in a 12-week supervised group exer-cise programme during treatment for early stage breast cancer and 87 were reassessed at the five-year follow-up.
The women who were more active consistently experienced lower levels of depression and increased quality of life compared to those who were less active.
After five years the women averaged three hours 20 minutes more physical activity each week than a control group who did not take part in the programme.
The research builds on previous work by Macmillan that showed patients with breast, bowel and prostate cancer were at less risk of their cancer recurr-ing and of dying from their illness if they did a recommended level of physical activity.
The charity now wants to work with the NHS and councils to develop exercise programmes aimed at getting cancer patients active.
Macmillan Scotland general manager Allan Cowie said: "Cancer patients have tradition-ally been told to rest, however this research shows there are real and long-lasting benefits to doing some exercise while going through treatment.
"And building on our previous research that found exercise makes some cancers less likely to return, it's clear that getting cancer patients to exercise is vital.
"We have already been working with partners to develop exercise programmes for cancer patients in parts of Scotland and want to continue work-ing with the NHS and local authorities to make the existing services responsive to the growing numbers of people affected by cancer."
Laura Simm, 52, from Lochwinnoch, who took part in the study said: "Since I took part in the programme I have endeavoured to do something every weekday morning.
"The most beneficial thing for me about taking part is how it helped me mentally.
"I suffer from fatigue, but find being active in the fresh air makes me feel more positive."