Physical activity after breast cancer may improve quality of life

Exercising often after breast cancer treatment ends may help women improve their quality of life over time, say researchers from the University of Illinois at Urbana-Champaign.

Background

Fatigue, weight gain, depression and other common side effects of breast cancer treatment contribute to lower reported levels of quality of life, a measure of a person’s life satisfaction. These side effects can begin or worsen even after treatment ends.

Physical activity has been shown to improve quality of life in women who completed breast cancer treatment, but the specific reasons why it works have been studied less often. Researchers wanted to know how physical activity affects a woman’s health status and self-efficacy, and how these factors then impact her quality of life.

Design

A group of 1,527 women diagnosed with breast cancer and who had computer access were asked to take part in a survey at the start of the study and again after 6 months. The survey included questions about

• their health and cancer history
• how often they participated in at least 10 minutes of hard, moderate or easy exercise in the 7 days before taking the survey, referred to as self-reported activity
  • hard, moderate and easy exercise were defined as activities equal to jogging, fast walking, and easy walking
• their self-efficacy, or whether they believed they were able to exercise for more or less time, at different levels of intensity, over varying lengths of time
• their health status, or their physical, social and family, emotional and functional wellness
• their global quality of life, a measure of their overall life satisfaction

In addition, 370 of these women were asked to wear an actigraph, a monitor that recorded their physical activity level. Actigraphs were worn during the day for 7 days in a row and collected data every minute.

Participants were mostly middle-aged and moderately overweight. On average they were 7 years post-diagnosis of early-stage breast cancer.

Moderately overweight was defined as a body-mass index (BMI) of 26.6. The BMI scale is a standard way doctors measure whether a person is overweight based on their height, age, and weight.

Results

Over 6 months, the women reported less activity; the actigraphs showed the same decline in physical activity.

The first survey results showed women who were more active reported a higher level of self-efficacy. These same women also reported higher physical, emotional, and functional well-being. In turn, women who expressed higher levels of these well-being categories reported significantly higher overall global quality of life.

Results of the survey taken at 6 months revealed that less activity led to reports of lower levels of self-efficacy. This in turn led to lower levels of well-being, which resulted in a significant decrease in reported quality of life.

These findings were largely the same when the researchers analyzed physical activity levels based on the actigraph data.

What this means for you

The findings of this study show that though physical activity and quality of life may not be directly related, getting more exercise after a breast cancer diagnosis can improve other areas of your life that have an impact on your overall quality of life.

Women who exercised more felt better about their physical, social and emotional health, and therefore reported that they were more satisfied with their lives. On the other hand, when women exercised less often, they felt worse about the same categories and felt less satisfied overall.

Researchers believe self-efficacy, a woman’s belief in her ability to be physically active, has a strong impact on whether she exercises and, in turn, on her life satisfaction after breast cancer. Physical activity programs post breast cancer treatment help raise women’s self-efficacy, encouraging participation and success, they suggest.

Phillips, S, McAuley, E. Physical activity and quality of life in breast cancer survivors: the role of self-efficacy and health status. Psycho-Oncology. (2014) 23: 27-34.