Abstract
BACKGROUND: Exercise has been shown to improve mental well-being and health-related quality of life (HRQoL) in breast cancer survivors. However, there is no evidence on the effects of online interventions tailored using heart rate variability (HRV). AIMS: This study analyzed the effects of online high-intensity interval and strength training, guided daily by autonomic modulation, compared to pre-planned moderate to high-intensity concurrent training and control, on HRQoL, pain, fatigue, anxiety, depression, life satisfaction, self-esteem, and fear of movement in breast cancer survivors. METHODS: A 16-week randomized controlled trial was conducted with 54 participants assigned to HRV-guided exercise, pre-planned exercise, or usual care. Participants trained aerobic and strength three times per week under real-time online supervision. Intensity was adjusted based on HRV for the HRV-guided group. HRQoL, anxiety, depression, life satisfaction, self-esteem and fear of movement were assessed pre- and post-intervention. RESULTS: Significant time-by-group interactions were found for HRQoL functional domains (physical p = 0.004, role p = 0.005, emotional p = 0.013, social p = 0.001) and symptoms (fatigue p < 0.001, pain p < 0.001, dyspnea p = 0.004, insomnia p = 0.012, constipation p = 0.014), as well as depression (p < 0.001), anxiety (p = 0.002), life satisfaction (p = 0.003), self-esteem (p = 0.024), and fear of movement (p = 0.015). HRV-guided exercise led to greater improvements, while the control group worsened. Moreover, the exploratory analysis suggested a higher degree of interconnected changes in the HRV-guided group, and that dyspnea and fatigue might be the variables most strongly connected with anxiety, depression, and functioning-related variables. CONCLUSION: Individualized online concurrent exercise, especially autonomic modulation-guided, improves HRQoL and mental health in breast cancer survivors, representing a promising personalized rehabilitation strategy.