Using ecological momentary assessment to understand associations between daily physical activity and symptoms in breast cancer patients undergoing chemotherapy.

Purpose: Understanding real-time relationships between physical activity (PA) and symptoms during chemotherapy (CT) could have important implications for intervention. This study used ecological momentary assessment to examine the relationship between objective PA and symptoms during CT.

Methods: Breast cancers patients (n = 67; M = 48.6 (SD = 10.3)) participated in data collection at three time points during CT: beginning, middle, and end. At each time point, participants answered four prompts assessing symptoms and wore an accelerometer for 10 days (3 days pre-CT, day of CT, and 6 days post-CT). Multilevel linear regression models examined the between- and within-person associations between moderate to vigorous (MVPA) and light-intensity physical activity (LPA) and same and next-day symptom ratings controlling for covariates.

Results: On days when individuals engaged in more LPA or MVPA, separately, they reported improved affect, anxiety, fatigue, physical functioning (walking and activities of daily living), pain, and cognition that day (p < 0.001 for all). Findings were consistent for next-day symptom ratings with the exception that only previous day LPA was related to next-day fatigue and neither LPA nor MVPA were related to next-day cognition (p < 0.001 for all). No between-person effects were found.

Conclusions: Within person higher than usual PA on a given day, regardless of intensity, is associated with improved symptoms ratings on the current and next day.

Implications For Cancer Survivors: Encouraging breast cancer patients undergoing CT to engage in daily PA could help manage CT-associated symptoms.