# Wearable-Based Assessment of Cardiac Recovery After a Modified Bruce Test in Women with Breast Cancer: Role of Physical Activity and Treatment Duration

## TL;DR

Wearable devices can track heart rate recovery after exercise in breast cancer patients, with physical activity and treatment duration influencing recovery patterns.

## Contribution

Identified a specific recovery interval (45–60 s) and validated wearable-based monitoring for cardiovascular assessment in breast cancer patients.

## Key findings

- Heart rate recovery showed a progressive decline with a significant difference at 45–60 s post-exercise.
- Weekly physical activity and treatment duration predicted heart rate recovery, but age did not.
- Wearable monitoring supports personalized exercise prescriptions for breast cancer patients.

## Abstract

What are the main findings?
Wearable heart rate monitoring identified a statistically differentiated recovery interval at approximately 45–60 s, reflecting a progressive HR decline rather than a discrete physiological threshold, following a Modified Bruce test in women with breast cancer.Weekly physical activity hours and oncological treatment duration were significant predictors of heart rate recovery, whereas age showed no significant association.

Wearable heart rate monitoring identified a statistically differentiated recovery interval at approximately 45–60 s, reflecting a progressive HR decline rather than a discrete physiological threshold, following a Modified Bruce test in women with breast cancer.

Weekly physical activity hours and oncological treatment duration were significant predictors of heart rate recovery, whereas age showed no significant association.

What are the implications of the main findings?
Wearable-based heart rate recovery assessment provides a feasible and practical tool for individualized cardiovascular monitoring in oncological exercise settings.Recovery intervals of around 45–60 s may be considered when designing personalized exercise prescriptions for women with breast cancer.

Wearable-based heart rate recovery assessment provides a feasible and practical tool for individualized cardiovascular monitoring in oncological exercise settings.

Recovery intervals of around 45–60 s may be considered when designing personalized exercise prescriptions for women with breast cancer.

Heart rate recovery (HRR) is an important indicator of cardiovascular autonomic function, yet evidence in women with breast cancer remains limited. This study aimed to analyze heart rate recovery during the first two minutes following a maximal exercise test and to examine its association with age, weekly physical activity, and oncological treatment duration using wearable technology. A cross-sectional design was applied in 22 women with breast cancer enrolled in an oncological exercise program. Participants performed a maximal treadmill test using the Modified Bruce Protocol, after which the mean heart rate was recorded across eight 15 s recovery intervals using a wearable chest-strap heart rate sensor integrated with an inertial device (WIMU PRO). Results showed a progressive and significant decrease in heart rate during recovery, with the first statistically significant pairwise difference emerging at 45–60 s post-exercise compared to the initial recovery interval (p < 0.05), within the context of a continuous HR decline. Regression analysis identified weekly physical activity hours (β = −0.281, p = 0.013) and oncological treatment duration (β = −0.245, p = 0.038) as significant predictors of mean heart rate recovery, explaining 4.8% of the variance, while age was not significantly associated (β = 0.049, p = 0.622). In conclusion, a differentiated recovery pattern emerged at approximately 45–60 s post-exercise, with weekly physical activity and oncological treatment duration as determinants. These findings support the use of wearable-based monitoring to inform individualized exercise prescription in women with breast cancer.