Activity behaviors of breast cancer survivors (BCSs) during treatment are unlikely to be at levels sufficient enough to gain health benefits. Previous activity research among BCSs has been mainly posttreatment and generally cross-sectional. This study aimed to determine the prevalence and changes in objectively measured moderate-to-vigorous physical activity (MVPA), light physical activity (LPA), and sedentary behavior (SED) among BCSs undergoing adjuvant/palliative therapy.
Participants completed baseline surveys and wore accelerometers to measure activity during waking hours during treatment and again 6 months later. Hierarchal linear modeling (HLM) was used to determine changes.
In total, 77 BCSs participated. Ninety-one percent provided physical activity (PA) data for 3 or more valid days at baseline (T 1) and 72% at 6 months (T 2); 29% met PA guidelines at T 1 and 41% at T 2. Daily LPA and SED did not change from T 1 to T 2 (133 vs 138 minutes; 595 vs 597 minutes). Controlling for body mass index at the intercept, HLM revealed that MVPA significantly increased from T 1 to T 2 (+5.62; P = .015).
An increase in objectively measured total daily MVPA over 6 months was found, at which time, fewer BCSs were currently receiving chemo- or radiotherapy and may theoretically be feeling better. However, fewer T 2 measures may bias and artificially inflate the results. Although total MVPA minutes increased at T 2, less than half BCSs were meeting guidelines and had high amounts of LPA/SED during treatment, with insignificant change over time (71% at T 1; 59% at T 2). Practitioner intervention may help reduce SED while increasing LPA and MVPA behavior among those currently undergoing treatment.
1Postdoctoral Fellow, Department of Medicine, Dalhousie University, Halifax, Nova Scotia, Canada
2Assistant Professor, School of Health and Human Performance, Dalhousie University, Nova Scotia, Canada
3Senior Research Scholar, Healthy Populations Institute, Dalhousie University, Halifax, Nova Scotia, Canada
4Professor, Division of Medical Oncology, Department of Medicine, Dalhousie University, Halifax, Nova Scotia, Canada
5Professor, Department of Medicine, Dalhousie University, Halifax, Nova Scotia, Canada
Correspondence: Cynthia C. Forbes, PhD, Centre for Clinical Research, QEII Health Sciences Centre, Room 205, 5790 University Ave, Halifax, NS B3H 1V7, Canada (firstname.lastname@example.org).
Grant Support: This research was supported by a grant from the Canadian Breast Cancer Foundation—Atlantic Chapter held by Dr Blanchard.
The authors declare no conflicts of interest.