This randomized controlled trial aims to investigate the clinical and functional effects of Whole Body Vibration (WBV) training when added to a standard pulmonary rehabilitation (PR) program in patients with fibrotic interstitial lung disease (ILD). Participants aged between 40 and 80 years with confirmed ILD diagnosis will be randomly assigned to two groups: (1) PR only (control), and (2) PR + WBV (intervention). The program will last for 8 weeks, with supervised sessions twice per week.

Primary outcome measures include pulmonary function (FEV₁, FVC), exercise capacity (6-minute walk test), dyspnea (mMRC and Borg scale), arterial blood gas analysis, depression level (Beck Depression Inventory), and disease-specific quality of life (St. George's Respiratory Questionnaire). WBV will be performed using a side-alternating vibration platform starting at 10 Hz and progressively increased up to 24-26 Hz over 8 weeks. All procedures will follow ATS/ERS guidelines.

This study is conducted at the Chest Diseases Department of Sultan Abdulhamid Han Training and Research Hospital in Istanbul under the supervision of a multidisciplinary team. The goal is to determine whether WBV offers additional benefit in improving functional outcomes, respiratory performance, and quality of life in ILD patients undergoing PR.

1. Study Background and Aim Interstitial lung disease (ILD) is characterized by inflammation and progressive fibrosis, leading to restrictive respiratory patterns, exertional dyspnea, and reduced exercise capacity. While pulmonary rehabilitation (PR) is a cornerstone of clinical management, data regarding the efficacy of Whole-Body Vibration Training (WBVT) in this population remain limited. The aim of this study is to investigate the effectiveness of WBVT applied in addition to a routine PR program consisting of respiratory muscle training, peripheral muscle training, and aerobic exercise in individuals with ILD. This randomized controlled trial comprehensively evaluates the clinical and functional effects of WBVT, focusing on lung functions, functional exercise capacity, gas exchange capacity via arterial blood gas analysis, multidimensional dyspnea levels, psychological status, and quality of life.

2. Study Design and Population This is a two-arm, prospective, randomized controlled trial conducted at the Pulmonary Rehabilitation Unit of the Pulmonology Department at Istanbul Sultan Abdülhamid Han Training and Research Hospital. Patients aged 40-80 years diagnosed with ILD will be screened. Following cardiovascular suitability clearance by a cardiologist, participants will be randomly assigned to either the Control Group (PR alone) or the Study Group (PR + WBVT) using a computer-based block randomization method. All procedures align with the Declaration of Helsinki, and written informed consent will be obtained.

3. INTERVENTIONS 3.1. Control Group (CG) - Standard Pulmonary Rehabilitation Participants in the control group will receive a supervised standard pulmonary rehabilitation (PR) program twice a week for 8 weeks. This program includes active cycle of breathing, diaphragmatic, and pursed-lip breathing techniques, alongside three structured training modalities. First, Inspiratory Muscle Training will be performed using the Powerbreathe Medic Plus (gray) device twice weekly, with the initial load set at a rating of perceived exertion (RPE) of 3-4 on the Modified Borg Scale and increased by 5-10% weekly (5 breaths × 6 sets). Second, Peripheral Muscle Training will target the quadriceps, shoulder flexors, and shoulder abductors at an RPE of 3-4, structured as 2 sets of 8 repetitions. Third, the Aerobic Exercise Program will be conducted on a cycle ergometer twice weekly for 21 minutes (3-minute warm-up, 15-minute target-intensity, and 3-minute cool-down) at 60-80% of the target heart rate calculated via the Karvonen formula, with pedal resistance adjusted weekly by 5-10% to maintain an RPE of 3-4.

   3.2. Study Group (SG) - Pulmonary Rehabilitation + Whole-Body Vibration Training (WBVT)Participants in the study group will receive the identical 8-week standard PR program described for the control group, combined with a supervised WBVT protocol performed twice a week using the Power Plate ProXG10 Acceleration Pro series platform. During WBVT, participants stand barefoot on the platform with slight knee flexion (~150°). Each session begins with a 5-minute warm-up (low-intensity treadmill walking/cycling and stretching) and concludes with a 5-minute cool-down consisting of static stretching. For the first 4 weeks, WBVT will be applied as 2 sets of 3 minutes with 2-minute rest intervals, starting at a frequency of 10 Hz and increasing by 2-3 Hz weekly based on tolerance. From week 5 through week 8, the training volume will increase to 3 sets of 3 minutes, progressively raising the frequency to reach a target of 24-26 Hz. The vibration amplitude will be kept constant at approximately 4-6 mm throughout the entire 8-week intervention.

4. STATISTICAL METHODOLOGY Sample Size and Statistical Analysis Based on a two-tailed independent samples t-test for the primary outcome, assuming a significance level of $\alpha = 0.05$, a statistical power ($1-\beta$) of 0.80, and an expected effect size of Cohen's $d = 1.15$ calculated via G*Power 3.1, a minimum sample size of 26 participants (13 per group) is required. To account for a potential 15% attrition rate, additional participants will be recruited. Statistical analysis will be performed using IBM SPSS Statistics V26.0 software. Normality will be assessed with the Shapiro-Wilk test. Continuous variables will be analyzed using Mixed Design ANOVA or appropriate parametric/non-parametric tests (Student's t-test, Paired t-test, Mann-Whitney U, Wilcoxon signed-rank) depending on the distribution of the data, with statistical significance set at $p < 0.05$.

Inclusion Criteria

• Ages 40 to 80 years
• Diagnosis of fibrotic interstitial lung disease confirmed by a multidisciplinary council (e.g., idiopathic pulmonary fibrosis, idiopathic nonspecific interstitial pneumonia, sarcoidosis, or other fibrotic patterns)
• Receiving stable pharmacological treatment for at least 3 months (e.g., antifibrotic or immunosuppressive therapy)
• No acute exacerbation or upper respiratory tract infection within the past 4 weeks
• Able to safely participate in pulmonary rehabilitation and whole-body vibration training as determined by clinical evaluation

Exclusion Criteria:

• Pulmonary hypertension with systolic pulmonary artery pressure >65 mmHg
• Severe cardiovascular disease (e.g., uncontrolled hypertension, congestive heart failure, recent myocardial infarction)
• Advanced renal or hepatic failure
• Balance disorders preventing safe standing on a vibration platform
• Severe musculoskeletal limitations (e.g., advanced arthritis, severe osteoporosis, high fall risk)
• Advanced cognitive impairment or dementia
• Severe psychiatric disorders (e.g., severe depression or anxiety)
• Neurological diseases interfering with participation or test performance
• Participation in a pulmonary rehabilitation program during the study or within the past 6 months
• Pregnancy or breastfeeding
• Uncontrolled metabolic diseases (e.g., advanced diabetes, uncontrolled thyroid dysfunction)
• Vestibular system disorders
• Active malignancy
• Presence of a pacemaker or other contraindicated implanted electronic devices

The study uses a single-blind design. Participants with interstitial lung disease are randomized into two parallel groups. The control group receives pulmonary rehabilitation only, including inspiratory muscle training, strengthening, and aerobic exercise twice weekly for 8 weeks. The experimental group receives the same rehabilitation program plus whole body vibration on a side-alternating platform (10-26 Hz). Outcome assessors are blinded to group allocation.

Primary outcomes are changes in six-minute walk distance, pulmonary function (FVC, FEV₁, FEV₁/FVC), and arterial blood gases (PaO₂, PaCO₂, SaO₂, pH, HCO₃-). Secondary outcomes include dyspnea (mMRC, Borg scale), depression (BDI), and quality of life (SGRQ).