Energy System Assessment in Survivors of Breast Cancer

Background Survivors of breast cancer commonly report functional limitations, including cancer-related fatigue (CRF) and decreased aerobic capacity. One key gap is addressing the 3 energy systems (aerobic, anaerobic lactic, and alactic), requiring assessment to establish a baseline exercise intensity and duration. Objective This study examined the feasibility of energy system–based assessment, also providing descriptive values for assessment performance in this population. Design This was a cross-sectional study. Methods Seventy-two posttreatment survivors of breast cancer were recruited. Following a baseline musculoskeletal assessment, women attempted 3 energy system assessments: submaximal aerobic (multistage treadmill), anaerobic alactic (30-second sit-to-stand [30-STS]), and anaerobic lactic (adapted burpees). Heart rate (HR) and rating of perceived exertion (RPE) were recorded. Secondary outcomes included body composition, CRF, and upper- and lower-limb functionality. Results Seventy of 72 participants performed the 30-STS and 30 completed the adapted burpees task. HR and RPE specific to each task were correlated, reflecting increased intensity. Women reported low-moderate levels of CRF scores (3% [2.1]) and moderate-high functionality levels (upper-limb: 65.8% [23.3]; lower-limb: 63.7% [34.7]). Limitations All survivors of breast cancer had relatively low levels of CRF and moderate functioning. Additionally, on average, participants were classified as “overweight” based on BMI. Conclusion This study is the first to our knowledge to demonstrate feasibility of energy system assessment in survivors of breast cancer. Using a combination of HR and RPE, as well as baseline assessment of each energy system, clinicians may improve ability to prescribe personalized exercise and give patients greater ability to self-monitor intensity and progress.