Neoplams, Patients, Cancer Survivors
Conditions
Keywords
Randomized Controlled Trial, Cluster Analysis, quality of life, physical functional performance, functional status, mental health
Brief summary
This study aims to compare an adapted plyometric strength-endurance exercise program with conventional strength training in women who are breast cancer survivors or currently undergoing treatment and who participate in provincial support associations. The goal is to determine whether a targeted plyometric intervention can provide additional benefits in physical and mental health outcomes. Using a cluster-randomized clinical trial design, the study will assess indicators such as functional capacity, muscle strength, fatigue levels, symptoms related to lymphedema, and overall quality of life. The findings are expected to contribute to a better understanding of how structured exercise programs can support recovery, physical function, and well-being in women affected by breast cancer.
Detailed description
Breast cancer is the most common malignancy among women worldwide. Despite significant advances in diagnosis and treatment that have improved survival rates, many patients and survivors continue to experience physical and psychological impairments that negatively affect their quality of life. Historically, intense or repetitive upper-limb exercise was discouraged due to concerns about triggering or worsening lymphedema. However, current evidence supports supervised therapeutic exercise as both safe and effective for this population. Strength training, in particular, has demonstrated benefits in muscle mass, physical function, bone health, fatigue reduction, and emotional well-being. Most existing research has focused on conventional strength training programs, leaving a gap in the evidence regarding more dynamic approaches, such as strength-endurance training involving plyometric exercises. Research on plyometrics within oncology remains limited and has been conducted primarily in pediatric populations, such as survivors of childhood leukemia or children with neurofibromatosis type 1. Nevertheless, plyometric training-traditionally used in athletic performance and in patients with neurological or musculoskeletal conditions-may offer significant therapeutic potential for women living with or recovering from breast cancer. Plyometric exercises are known to enhance muscular power, balance, proprioception, and neuromuscular control, all of which are essential for restoring functional capacity and independence. Their dynamic, progressive nature may also support greater motivation and adherence, potentially translating into improvements in mental health, self-esteem, and body image. In summary, plyometric-based strength-endurance training represents an innovative and promising approach to improving quality of life, functional performance, and overall well-being in women who are survivors of breast cancer or currently undergoing treatment. This study aims to address the existing evidence gap by evaluating the therapeutic effects of an adapted plyometric program compared with conventional strength training within a controlled clinical trial framework.
Interventions
OTHERPlyometric Strength-Endurance Training
Participants in the experimental group will take part in an adapted plyometric strength-endurance training program delivered through supervised 60-minute sessions, twice per week, over a 12-week period (24 sessions total). A minimum rest interval of 48 hours will be maintained between sessions. The frequency and duration of the intervention follow the recommendations of the National Strength and Conditioning Association (NSCA) for safe implementation of plyometric and strength-endurance exercise in adult populations.
Participants assigned to the control group will perform a conventional strength training program. This program has been designed as an active and structured intervention to allow a meaningful comparison with the effects of the plyometric training implemented in the experimental group. The exercise circuit will include functional movements aimed at global strengthening, with an emphasis on multi-joint patterns that promote transfer of improvements to activities of daily living.
Sponsors
University of Vigo
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT
Masking
DOUBLE (Subject, Outcomes Assessor)
Eligibility
Sex/Gender
FEMALE
Age
18 Years to No maximum
Healthy volunteers
No
Inclusion criteria
* Women aged 18 years or older. * Prior diagnosis of breast cancer. * History of mastectomy, including unilateral procedures, total breast surgery, or breast-conserving surgery. * Completion of postoperative chemotherapy or radiotherapy, when indicated. * Absence of contraindications for physiotherapy or therapeutic exercise. * Willingness to voluntarily participate in the study. * Ability to understand and sign the informed consent form. * Availability to participate in the training program for the entire intervention period (approximately 12 weeks).
Exclusion criteria
* Participants will be excluded if any of the following conditions are present: * Active metastasis to other organs or tissues (e.g., liver, kidney, lung, brain) or stage IV cancer that prevents safe participation in the therapeutic exercise program. * Current diagnosis of cardiovascular, respiratory, neuromuscular, or musculoskeletal diseases that contraindicate physical exercise or impair safe completion of the program. * Major surgery within the previous 6 months without medical clearance to resume physical activity. * Cognitive impairment or mental health conditions that limit comprehension of instructions or safe engagement in the intervention. * Current pregnancy. * Lack of medical clearance for moderate-to-vigorous physical activity (as indicated by a medical certificate specifying the duration of the restriction and the conditions under which exercise may be resumed).
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Quality of life (Breast Cancer-Specific Quality of Life) | From enrollment to the end of treatment at 12 weeks, followed by an additional 12-week follow-up period | EORTC QLQ-BR42: European Organisation for Research and Treatment of Cancer (EORTC) to assess breast cancer-specific quality of life. Description: The EORTC QLQ-BR42 is a validated 42-item questionnaire designed to assess breast cancer-specific quality of life. It evaluates physical, emotional, and functional well-being, as well as symptoms and treatment-related side effects relevant to contemporary breast cancer therapies. The measure covers domains such as body image, sexual functioning, systemic therapy side effects, breast symptoms, and arm symptoms. Scoring: Items are scored according to the EORTC scoring manual. Scores are linearly transformed to a 0-100 scale. Higher scores on functional scales indicate better functioning; higher scores on symptom scales indicate greater symptom burden. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Cardiorespiratory capacity | From enrollment to the end of treatment at 12 weeks, followed by an additional 12-week follow-up period | 6-Minute Walk Test (6MWT) Description: The Six-Minute Walk Test is a standardized assessment of cardiorespiratory capacity that measures the total distance walked (in meters) over a six-minute period at a self-paced speed. It reflects functional exercise tolerance and global physical endurance. Score Range: Minimum possible score: 0 meters Maximum possible score: No fixed upper limit (performance-dependent; healthy individuals may reach 300-700 meters) Interpretation: Higher scores indicate a better outcome, reflecting greater cardiorespiratory capacity. |
| Cancer-related fatigue | From enrollment to the end of treatment at 12 weeks, followed by an additional 12-week follow-up period | FACIT-F (Functional Assessment of Chronic Illness Therapy - Fatigue) Description: The Functional Assessment of Chronic Illness Therapy - Fatigue Subscale (FACIT-Fatigue) is a validated patient-reported questionnaire assessing cancer-related fatigue and its impact on daily functioning. It contains 13 items, each rated on a Likert scale from 0 ("not at all") to 4 ("very much"). Score Range: Minimum possible score: 0 points (indicates the worst fatigue) Maximum possible score: 52 points (indicates the least fatigue) Interpretation: Higher scores indicate a better outcome, representing less fatigue and better functional well-being. |
| Mobility and range of motion | From enrollment to the end of treatment at 12 weeks, followed by an additional 12-week follow-up period | Goniometry and flexibility testing Description: Goniometric and flexibility tests will be used to assess joint mobility of the upper and lower limbs and trunk. Goniometry quantifies joint range of motion in degrees using a standardized instrument (goniometer), while flexibility tests measure muscle and soft-tissue extensibility. These tests evaluate functional mobility relevant to daily activities. Score Range: Minimum: 0 degrees (no active movement) Maximum: varies by joint Interpretation:Higher scores indicate better mobility and joint range of motion. |
| Muscle strength | From enrollment to the end of treatment at 12 weeks, followed by an additional 12-week follow-up period | Hand-held dynamometry (MicroFET II - Maximal isometric strength) Description: Maximal isometric strength will be assessed using a hand-held dynamometer (MicroFET II). This device measures force output (in Newtons or kilograms-force) during standardized resisted movements of the upper limb. Score Range: Minimum: 0 (no measurable force) Maximum: device-dependent; MicroFET II typically measures up to 300 pounds-force (≈1334 N), though functional values are lower in clinical practice. Interpretation: Higher scores indicate a better outcome, reflecting greater muscular strength. |
| Proprioception | From enrollment to the end of treatment at 12 weeks, followed by an additional 12-week follow-up period | Outcome measure: Joint position sense and force-matching tests Description: Proprioception will be evaluated using joint position sense testing (ability to reproduce specific joint angles) and force-matching tasks (ability to replicate a target force level). These tests assess neuromuscular control, sensorimotor acuity, and accuracy in joint and force detection. Score Range: Joint position sense: error values typically expressed in degrees (°). Minimum error: 0° (perfect accuracy) Maximum error: no fixed upper limit; depends on test range Force-matching: error expressed as difference from target force. Minimum error: 0 (perfect accuracy) Maximum: no predefined limit Interpretation: Lower error values indicate a better outcome (greater proprioceptive accuracy). |
| Upper limb functionality | From enrollment to the end of treatment at 12 weeks, followed by an additional 12-week follow-up period | Outcome measure 1: Disabilities of the arm, shoulder and hand questionnaire (DASH) Description: The DASH is a 30-item patient-reported outcome measure assessing physical function and disability of the upper limb. It evaluates difficulty performing daily activities, symptom severity, and functional limitations. Score Range: Minimum: 0 (no disability → best outcome) Maximum: 100 (severe disability → worst outcome) Interpretation: Higher scores indicate a worse outcome (greater disability). Outcome Measure 2: Constant-Murley shoulder score Description: The Constant-Murley Score is a clinician-reported composite measure evaluating shoulder function through four domains: pain, daily living activities, range of motion, and strength. Total score ranges from 0 to 100. Score Range: Minimum: 0 (worst shoulder function) Maximum: 100 (normal shoulder function) Interpretation: Higher scores indicate a better outcome (greater shoulder function). |
| Presence of lymphedema | From enrollment to the end of treatment at 12 weeks, followed by an additional 12-week follow-up period | Outcome measure: Presence of lymphedema (Yes/No), symptom severity, and limb circumference measurements. Description: Lymphedema will be assessed through a combination of: * Presence/absence (Yes/No) of swelling; * Subjective symptoms (heaviness, tightness, pain) measured using a visual analog scale (0-10); * Circumference measurements (circumetry) at standardized anatomical points of the upper limb. Score Range: Visual analog scale: 0 (no symptoms) to 10 (worst symptoms). Circumference: no fixed minimum/maximum, values recorded in centimeters. Interpretation: Higher symptom scores and larger circumference values indicate worse lymphedema. |
| Sleep quality | From enrollment to the end of treatment at 12 weeks, followed by an additional 12-week follow-up period | Outcome measure: Pittsburgh Sleep Quality Index (PSQI) Description: The PSQI evaluates overall sleep quality across seven components (sleep latency, duration, efficiency, disturbances, etc.). The questionnaire includes 19 items. Score Range: Minimum: 0 Maximum: 21 Higher scores = worse sleep quality. Interpretation: A global score \> 5 typically indicates poor sleep quality. |
| Kinesiophobia | From enrollment to the end of treatment at 12 weeks, followed by an additional 12-week follow-up period | Tampa Scale for Kinesiophobia - 11-item Version (TSK-11) Description: The TSK-11 assesses the fear of movement or reinjury, using 11 Likert-scale items rated from 1 (strongly disagree) to 4 (strongly agree). Score Range: Minimum: 11 Maximum: 44 Higher scores indicate greater fear of movement. Interpretation: Higher scores = worse outcome. |
| Enjoyment of physical activity | From enrollment to the end of treatment at 12 weeks, followed by an additional 12-week follow-up period | Measure 1: Enjoyment of physical activity (Physical Activity Enjoyment Scale - PACES-18) Description: 18-item validated scale assessing enjoyment of physical activity; items rated on a 7-point Likert scale. Score Range: Min: 18 (lowest enjoyment) Max: 126 (highest enjoyment) Interpretation: Higher scores = greater enjoyment of physical activity. Measure 2: Leisure-Time Physical Activity (Leisure-Time Physical Activity Questionnaire) Description: Self-reported weekly minutes of moderate and vigorous physical activity performed during leisure time. Score Range: Min: 0 minutes/week Max: No fixed upper limit Interpretation: Higher scores = greater leisure-time physical activity (better outcome). |
| Exercise adherence rate | From enrollment to the end of treatment at 12 weeks, followed by an additional 12-week follow-up period | Description: Adherence will be calculated using the formula: (Number of sessions completed / Number of scheduled sessions) × 100. Score Range: Minimum: 0% Maximum: 100% Interpretation: Higher percentages indicate better adherence. |
| Intervention acceptability | To the end of treatment at 12 weeks | Custom Likert-Scale Acceptability Questionnaire (Ad Hoc) Description: A custom Likert-type questionnaire (1-5) will evaluate the participant's perceived acceptability of the intervention, including clarity, comfort, and usability. Score Range: Minimum: 1 (least acceptable) Maximum: 5 (most acceptable) Interpretation: Higher scores indicate greater acceptability. |
| Satisfaction with the intervention | To the end of treatment at 12 weeks | Custom Likert-Scale Satisfaction Questionnaire (Ad Hoc) Description: A custom Likert-scale questionnaire will assess participant satisfaction with the intervention, including perceived usefulness and overall experience. Score Range: Minimum: 1 (least satisfied) Maximum: 5 (most satisfied) Interpretation: Higher scores indicate greater satisfaction |
| Adverse events | To the end of treatment at 12 weeks | Systematic adverse event log Description: Systematic recording of any adverse events occurring during the program, documented according to standard clinical criteria. Score Range: Not applicable (qualitative/quantitative event logging) Interpretation: Higher number or severity of adverse events indicates poorer safety. |
| Back pain | From enrollment to the end of treatment at 12 weeks, followed by an additional 12-week follow-up period | Outcome measure: Brief Pain Inventory (BPI) Description: The Brief Pain Inventory assesses pain intensity (0-10) and pain interference with daily activities. Score Range: Intensity: 0 = no pain; 10 = worst imaginable Interference score: 0 = no interference; 10 = complete interference Interpretation: Higher scores indicate worse pain and greater functional impact. |
| Pelvic Floor distress | From enrollment to the end of treatment at 12 weeks, followed by an additional 12-week follow-up period | Pelvic Floor Distress Inventory (PFDI) Description: The Pelvic Floor Distress Inventory evaluates symptoms of pelvic floor dysfunction, including urinary, colorectal, and pelvic organ prolapse symptoms. Score Range: Minimum: 0 Maximum: 300 (depending on subscales used) Interpretation: Higher scores indicate greater symptom burden (worse outcome). |
Countries
Spain
Contacts
CONTACTYoana Gonzalez-Gonzalez, PhD
CONTACTGloria María Cascallar Cascallar, Graduate
PRINCIPAL_INVESTIGATORYoana Gonzalez Gonzalez, PhD
University ofVigo
PRINCIPAL_INVESTIGATORGloria M Cascallar Cascallar, Graduate
SERGAS (Servicio galego de Saúde), Galician Health Service, Spanish Social Security System
Outcome results
None listed