Long-Term Effects of Multicomponent Training in Breast Cancer Survivors: Clinical Outcomes and Implications
Samuel Gonçalves Almeida da Encarnação, André Schneider, Roberto Gonçalves Almeida da Encarnação, Luciano Bernardes Leite, Pedro Forte, Helder Jaime Fernandes & António Miguel Monteiro Scientific Reports | (2025) 15:33806 | https://doi.org/10.1038/s41598-025-01702
Summary: At Cancer Fitness, Jay K. Harness, MD
Background
Breast cancer remains the most prevalent malignancy worldwide, with over 2.3 million new cases diagnosed annually and survival often complicated by long-term treatment effects such as fatigue, sarcopenia, osteoporosis, and cardiovascular disease. These sequelae impair functional capacity and quality of life. Exercise interventions have emerged as key non-pharmacological strategies to counteract these issues, but there is limited evidence regarding long-term, multicomponent programs—those combining strength, aerobic, flexibility, and balance training.
Study Design
This controlled experimental trial investigated the 32-week effects of a structured, multicomponent training program on body composition and physical fitness among 19 breast cancer survivors (mean age ~64 years). Seven women were allocated to the exercise group (EG), completing three supervised sessions per week, while twelve formed the control group (CG), instructed to maintain daily routines without structured exercise. Bayesian statistical analyses were applied to account for small sample size.
Key Clinical Outcomes
Body Composition
- Weight and Body Fat: The EG demonstrated significant reductions in body weight (−1.67 kg; Bayes Factor [BF] = 15.15) and body fat percentage (−3.99%; BF = 34.87).
- Other Parameters: No meaningful changes were observed in BMI, lean mass, visceral fat, body water, or basal metabolism. Importantly, lean mass was preserved, which is clinically relevant for preventing sarcopenia—a common complication in survivors.
Physical Fitness
Improvements in functional outcomes were striking and clinically meaningful:
- Upper Limb Strength: +14.14 repetitions overall (Cohen’s d = 3.45), with notable gains even in the surgically affected arm (+13.57 repetitions). This has direct implications for restoring daily upper-body functions, such as self-care, food preparation, and household tasks.
- Lower Limb Strength: +7.86 repetitions (Cohen’s d = 2.24), supporting mobility and independence in walking, stair climbing, and carrying objects.
- Aerobic Capacity: +97.57 repetitions in the 2-minute step test (BF = 157.28), reflecting better cardiovascular fitness, reduced fatigue, and enhanced tolerance for physical activity.
- Flexibility and Balance: Moderate to large effect size improvements were observed, lowering fall risk and enhancing mobility—especially critical in older survivors.
No adverse events or injuries were reported, confirming the safety of long-term multicomponent training.
Clinical Importance of Findings
The clinical outcomes underscore several points:
- Functional Recovery: Gains in upper and lower limb strength translate into meaningful improvements in independence and quality of life. Restoring function in surgically affected arms is particularly important for daily living and psychosocial recovery.
- Cardiometabolic Health: Aerobic fitness improvements can lower cardiovascular risk, a leading cause of death in breast cancer survivors, and help mitigate treatment-induced fatigue.
- Body Composition: Reduction in adiposity without lean mass loss addresses “inflammaging,” lowering chronic inflammation and potentially reducing recurrence risk. While BMI and visceral fat did not change significantly, the decrease in overall body fat percentage is clinically significant.
- Safety and Sustainability: The absence of adverse events highlights that supervised, progressive, multicomponent programs are safe, even in older women with prior cancer treatment.
- Individualized Responses: Cluster analysis revealed heterogeneity in responsiveness, suggesting the need for tailored exercise prescriptions. Like medication titration, exercise programs should be periodically adapted based on individual progress.
Limitations
The small sample size and unequal follow-up duration between groups limit generalizability. Lack of interim assessments prevented understanding the trajectory of improvements. Nutritional and lifestyle factors were not tracked, which may influence responsiveness.
Conclusions
This study provides compelling evidence that 32 weeks of multicomponent training meaningfully improves functional fitness and moderately enhances body composition in breast cancer survivors. Clinically, these outcomes support integrating long-term, structured, multicomponent exercise into survivorship care plans as a safe, effective, and sustainable strategy to restore independence, reduce comorbidity risk, and enhance quality of life. Future research with larger, more diverse cohorts is needed, but this study strengthens the case for exercise as frontline supportive therapy in oncology rehabilitation.
