Lack of exercise may have a deleterious effect on breast cancer survival and increases the risk of recurrence, suggests a new study.
The study by US researchers reveals only one third of the breast cancer survivors meet physical activity requirement, which is known to aid recovery.
The findings have been published in the journal Cancer.
The results seem alarming especially for the US and the UK where an adult is recommended to do either 150 minutes of moderate-intensity or 75 minutes of vigorous-intensity exercise each week.
However, the study found that only 35% of women breast cancer survivors met these guidelines.
According to UK breast cancer groups, women who had experienced breast cancer need extra support to follow physical activity guidelines for recovery.
"Although this study was conducted in America rather than the UK, the results suggest that women who have received a breast cancer diagnosis need better support to keep active," Caroline Dalton, of Breakthrough Breast Cancer, told BBC News.
"There are no specific guidelines in place at the moment to tell us precisely how much physical activity is needed after a breast cancer diagnosis," she says.
Breakthrough Breast Cancer recommends at least 3.5 hours of exercise per week, she said. She added that a breast cancer survivor should check with her treatment team to know the appropriate timing to start exercising.
"This study serves as a reminder of how important it is that women with breast cancer are made aware that physical activity can improve their chances of survival," Baroness Delyth Morgan, chief executive of the campaign group, said.
"Recent research has shown that even small increases to the amount of exercise done after a breast cancer diagnosis can give women a better chance of survival.
"This is why it is essential that women are given a clear written follow-up care plan, which should include practical advice about diet and exercise," she added.