Is Quality of Life Related to Cardiorespiratory Fitness in Overweight and Obese Breast Cancer Survivors?

This study assessed changes in quality of life (QoL) and cardiorespiratory fitness (CRF) during a diet and physical activity (PA) intervention in breast cancer (BC) survivors and investigated the relation between these changes. The intervention of this single-arm pre-post study involved supervised, 1-hour weekly, diet sessions and 75-minute bi-weekly PA sessions of moderate-to-high intensity. This 12-week intervention targeted overweight/obese women who had recently completed BC treatment. Pre- and post-CRF and QoL measurements were compared using paired t-tests. Linear regression models, including baseline participants' characteristics and weight change, were used to assess the association between changes in CRF and QoL. The 37 BC survivors who completed the intervention between May 7, 2012 and July 27, 2012 showed significant increases in CRF and QoL. Peak oxygen uptake (mL/kg/min) increased from 19.0 ± 2.8 to 24.0 ± 4.1 while peak workload (watts/kg) increased from 1.3 ± 0.3 to 1.7 ± 0.3. Although statistical significance was not reached, the increase in workload seemed associated with increases in physical, mental, and general health and with a decrease in fatigue. This lifestyle intervention improved BC survivors' QoL and CRF and suggested possible relationships between CRF and QoL. More research needs to confirm these associations and promote lifestyle interventions aiming at improving BC survivors' QoL.