Effects of a Six-week Pedometer-based Walking Programme on Physical Activity Level, Body Composition and Antioxidant Level in Breast Cancer Survivors: a Randomized Controlled Trial

Abstract Background: Breast cancer risk is associated with body composition indices especially waist-hip ratio-≥0.85 (which defines central adiposity), body mass index ≥30Kg/m2 (which defines obesity), percentage body fat mass-≥25Kg/m2 (which defines general adiposity), and physical inactivity (defined as <600(MET-min/week or ≤7999 step counts/day). Physical inactivity promotes inflammatory micro-environment, oxidative stress and diminish antioxidant (superoxide dismutase) level, similar to adiposity but unlike physical activity. Therefore, a pedometer-based walking programme may improve body composition, physical activity and Superoxide dismutase levels in breast cancer survivors, thus preventing breast cancer recurrence. Methods: This study is a single-blind randomized controlled trial involving 80 participants from the Oncology Clinic, who were consecutively stratified according to their baseline physical activity level (MET-min/week), and step count/day obtained using a Fitbit Charge HR pedometer. The experimental group received an intervention programme to improve physical activity level by setting weekly targets of additional 1500 steps to the baseline value, while the control group did not change their physical activity tasks for the duration of the study. Data were collected with the short form of International Physical Activity Questionnaire at baseline and the 6th week, and weekly from the Fitbit server/data centre, which receives transmitted data from the pedometer customised to each participant. Data were analysed using simple descriptive statistics, multiple regression analysis, and independent t-test at p<0.05, one-tailed test. Results: There was a significant increase in step counts/day (p=0.0002), physical activity level(MET-min/week) (p=0.006), and Superoxide dismutase level(p=<.0001), with a decrease in waist-Hip Ratio (p=0.002), and percentage body fat mass (p=0.01), unlike the body mass index (p=0.09) in the intervention group compared to control.Conclusion: Physical activity, Superoxide dismutase level and body composition may be improved through a pedometer-based walking programme and possibly the prognosis of breast cancer recurrence. Trials Registration number: PACTR202001542824141.