Facility-Based Multi-Modal Rehab vs. Home-Based Resistance Exercise for Quality of Life in Breast Cancer Survivors

Breast cancer treatments, including chemotherapy and radiotherapy, are associated with sarcopenia, a loss of muscle mass and strength, which increases toxicity, surgical complications, and mortality risk. While resistance exercise is known to mitigate muscle loss, the synergistic effect of adding relaxation techniques to address the psychological and neuromuscular tension of cancer treatment is not well established. This study investigates the comparative effectiveness of a multi-modal, facility-based program (elastic band resistance exercise combined with progressive muscle relaxation) versus a self-directed home-based elastic band resistance exercise program. The supervised, multi-modal intervention is hypothesized to offer superior results in muscle mass, physical performance, and quality of life compared to isolated resistance training.

• Multimodal Resistance and Relaxation Training (Behavioral): A 16-week multimodal program consisting of resistance exercise and relaxation training. Participants undergo two sessions per week: one weekly session is conducted under the supervision of a physical therapist at Taipei Tzu Chi Hospital, and one weekly session is self-directed and performed by the participant in a home setting. The resistance exercise portion utilizes progressive elastic band training
• Home-Based Resistance Exercise Training (Behavioral): A 16-week self-directed resistance exercise program. The intervention consists of two sessions per week performed independently by the participant in a home setting. The exercise regimen utilizes progressive elastic band training and is conducted without direct therapist supervision

Primary outcomes

• Change from Baseline in Skeletal Muscle Mass Index (SMI) [16 weeks]: Skeletal Muscle Mass Index (SMI) is calculated by dividing total skeletal muscle mass (kg), as measured by bioelectrical impedance analysis (ACCUNIQ BC720; SELVAS Healthcare), by the square of the height (m²). Higher scores indicate greater muscle mass relative to height (better outcome).

Secondary outcomes

• Functional Battery: Change from Baseline in Handgrip Strength [16 weeks]: Handgrip strength of the dominant hand measured using a hydraulic dynamometer (LiTE - 200 lb Capacity, USA); the highest of three trials is reported. Higher scores indicate greater upper extremity strength (better outcome).
• Functional Battery: Change from Baseline in 4-Meter Gait Speed [16 weeks]: 4-meter gait speed (m/s) measured using a standardized timed walk test. Higher scores indicate faster walking speed (better outcome).
• Functional Battery: Change from Baseline in Timed Up & Go (TUG) Test [16 weeks]: Functional mobility and balance measured using the Timed Up \& Go (TUG) test; time recorded in seconds. Higher scores (longer time taken) indicate poorer functional mobility and balance (worse outcome).
• Functional Battery: Change from Baseline in 30-Second Chair Stand Test [16 weeks]: Lower extremity functional strength measured as the total number of stands completed in 30 seconds.
• Body Composition: Change from Baseline in Body Fat Mass [16 weeks]: Body fat mass (kg) measured using bioelectrical impedance analysis (ACCUNIQ BC720; SELVAS Healthcare). Higher scores indicate greater absolute body fat (worse outcome in the context of sarcopenia/obesity).
• Body Composition: Change from Baseline in Limb-to-Trunk Lean Mass Ratio [16 weeks]: The ratio of total limb lean soft tissue (kg) to trunk lean soft tissue (kg) derived from segmental bioelectrical impedance analysis (ACCUNIQ BC720; SELVAS Healthcare). Higher scores indicate a higher proportion of appendicular muscle relative to the trunk (better outcome).
• Body Composition: Change from Baseline in Arm-to-Leg Lean Mass Ratio [16 weeks]: The ratio of total arm lean soft tissue (kg) to total leg lean soft tissue (kg) derived from segmental bioelectrical impedance analysis (ACCUNIQ BC720; SELVAS Healthcare). Higher scores indicate greater upper limb muscle mass relative to lower limb mass.
• HRQoL: Change from Baseline in EORTC QLQ-C30 Score [16 weeks]: Quality of life measured by the EORTC QLQ-C30; raw scores are transformed to a standardized 0-100 scale. For Global Health Status and Functional scales, higher scores indicate better quality of life/functioning (better outcome). For Symptom scales/items, higher scores indicate a higher level of symptomatology/problems (worse outcome).
• HRQoL: Change from Baseline in EORTC QLQ-BR45 Score [16 weeks]: Breast cancer-specific quality of life measured by the EORTC QLQ-BR45; raw scores are transformed to a standardized 0-100 scale. For Functional scales (e.g., Body Image, Sexual Functioning), higher scores indicate a higher/healthier level of functioning (better outcome). For Symptom scales/items (e.g., Systemic Therapy Side Effects, Arm Symptoms), higher scores indicate a higher level of symptomatology/problems (worse outcome).
• HRQoL: Change from Baseline in SarQoL Score [16 weeks]: Sarcopenia-specific quality of life measured by the SarQoL questionnaire; composite score transformed to a 0-100 scale. Higher scores indicate a better quality of life (better outcome).

Sex: Female, ages: 18 Years to any

Inclusion Criteria:

* Histologically confirmed primary breast cancer
* Stage I-III non-metastatic breast cancer following lumpectomy or mastectomy
* Completed adjuvant chemotherapy (with or without radiotherapy)
* Age ≥ 18 years
* Able to understand and follow the study protocol
* Willingness to attend facility-based exercise training.

Exclusion Criteria:

* Metastatic (Stage IV) breast cancer
* Morbid obesity (BMI > 40 kg/m²)
* Uncontrolled hypertension (systolic blood pressure > 180 mmHg and/or diastolic blood pressure > 99 mmHg)
* Presence of implantable medical devices (e.g., pacemakers, nerve stimulators)
* Presence of metallic surgical implants (e.g., total hip or knee replacements) that interfere with assessment devices
* Contraindications for resistance training (e.g., acute infectious disease, severe cardiac disease, severe respiratory insufficiency)
* Concurrent malignant diseases
* Current participation in intense systematic exercise training (defined as at least 1 hour, twice per week)
* Previous participation in an exercise intervention clinical trial.