Digest commentators: Lauren C. Capozzi & S. Nicole Culos-Reed

Digest editor: Jennifer Brunet, University of Ottawa

It has been well established that exercise has numerous benefits for cancer survivors, both during and after treatment. In a population where psychosocial concerns like fatigue, pain, anxiety, depression, and decreased physical functioning are a reality for most patients, exercise can positively impact overall quality of life (QOL). But how does this happen? There are few researchers who have examined the underlying mechanisms responsible for improvements in QOL in patients with cancer who exercise. Identifying these mechanisms will aid in developing better targeted interventions, which will likely enhance the impact of exercise interventions on QOL.

Buffart and colleagues were determined to further analyze the factors mediating improvements in QOL during a 12-week group-based exercise program. They hypothesized that the intervention would increase activity levels, as well as perceptions of general self-efficacy and mastery. In turn, this would decrease fatigue and distress, which would then improve QOL. For their study, which was part of a larger multi-site trial, they recruited 209 patients diagnosed with different types of cancer who were on average 48.8 ± 10.9 years of age. A total of 147 patients were included in the exercise intervention group, and 62 were included in the wait list control group. The exercise intervention consisted of two weekly sessions targeting aerobic and strength components.

Interestingly, Buffart and colleagues found that there was no significant direct effect of the group-based exercise intervention on QOL. Rather, the intervention had an indirect positive effect on QOL. Specifically, the intervention positively impacted QOL by increasing physical activity, self-efficacy, and mastery, and subsequently decreasing fatigue and distress. The improvements in fatigue management were partially explained by the indirect effect of increased physical activity and self-efficacy, while the improvements in distress management were partially explained by the indirect effect of increased self-efficacy and mastery. Increased physical activity was directly linked to enhanced QOL. This study not only supports previous findings linking exercise with symptom management and QOL, but also provides insight into the mechanisms linking exercise with improvements in QOL. Accordingly, researchers and health professionals developing exercise intervention should consider approaches and strategies shown to increase perceptions of self-efficacy and mastery as this may decrease fatigue and distress, and in turn improve QOL.

Why I liked this article?

This article is important as it helps identify ways through which exercise can lead to improvements in QOL. This knowledge is also valuable when considering the design of effective exercise interventions as well as sustainable clinic or community-based exercise programs for cancer patients. Further work in this area is needed to identify additional pathways that are perhaps unique to specific cancer groups so we can not only develop targeted interventions, but also developed tailored intervention for patient diagnosed with different types of cancer.

Article: Buffart, L. M., Ros, W. J. G., Chinapaw, M. J. M., Brug, J., Knol, D. L., Korstjens, I., Weert, E van, Mesters, I., Borne, B. van den, Hoekstra-Weebers, J. E. H. M., May, A. M. (2014). Mediators of physical exercise for improvement in cancer survivors’ quality of life. Psycho-oncology, 23: 330-338.

Journal website: http://onlinelibrary.wiley.com/journal/10.1002/(ISSN)1099-1611

Author website: http://www.emgo.nl/team/924/laurienbuffart/personal-information/