Brain and Peripheral Muscle Oxygenation in Patients With Chronic Obstructive Pulmonary Disease

This interventional study aims to investigate the acute effects of different types of exercise on cerebral and peripheral muscle oxygenation in patients with chronic obstructive pulmonary disease (COPD). Functional near-infrared spectroscopy (fNIRS) and near-infrared spectroscopy (NIRS) will be used simultaneously to measure oxygenation changes in the prefrontal cortex and the vastus lateralis muscle during rest, Stroop task performance, the six-minute walk test, aerobic, strengthening, and breathing exercises.

The study will compare COPD patients and age- and sex-matched healthy controls to determine how brain and muscle oxygenation responses differ between groups and among exercise modalities. The findings are expected to guide the design of safe, individualized pulmonary rehabilitation programs that optimize oxygenation without compromising safety.

Study Overview

• Status: Recruiting
• Conditions: Copd
• Intervention / Treatment: Other: Aerobic Exercise (Treadmill Walking); Other: Resistance Exercise (Upper and Lower Limb Strength Training); Other: Breathing Exercises; Other: Cognitive Task (Stroop Task)

Detailed Description

Functional near-infrared spectroscopy (fNIRS) and near-infrared spectroscopy (NIRS) allow real-time, non-invasive assessment of tissue oxygenation. Although widely used in neurology and exercise physiology, their application in pulmonary diseases such as COPD remains limited.

This study is designed as a non-randomized controlled, multidisciplinary trial conducted at Yedikule Chest Diseases and Thoracic Surgery Training and Research Hospital, Istanbul. The research team includes specialists in physiotherapy and rehabilitation, pulmonology, and neuroscience.

Participants will undergo a single standardized pulmonary rehabilitation (PR) session comprising three exercise modalities:Aerobic training, Peripheral strengthening exercises and Breathing exercises.

Before and after exercise, participants will perform the Stroop cognitive task to evaluate executive function and its relationship with cerebral oxygenation. Continuous fNIRS and NIRS monitoring will occur at rest, during each exercise, and during recovery.

• Study Type: Interventional
• Enrollment (Estimated): 60
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Esra Pehlivan; Phone Number: +90216 777 87 77; Email: esra.pehlivan@sbu.edu.tr

Study Locations

• Turkey (Türkiye)
  • Istanbul, Turkey (Türkiye), 34668
    • Recruiting
    • Esra Pehlivan
    • Contact: Esra Pehlivan; Phone Number: +90 216 777 8 777; Email: esra.pehlivan@sbu.edu.tr

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: Yes

Description

Inclusion Criteria

• Age 40-70 years
• Diagnosis of moderate-to-severe COPD (GOLD stage II-III)
• Stable disease (no exacerbation in previous 4 weeks)
• BMI 18.5-24.9 kg/m²
• Manual muscle strength ≥ 4 (MRC scale)
• Ability to perform exercise tests safely
• Written informed consent

Exclusion Criteria

• Severe comorbid conditions (uncontrolled cardiac, neurological, or orthopedic disease)
• Need for high-flow oxygen therapy (>2 L/min)
• History of cerebrovascular disease or transient ischemic attack
• Musculoskeletal or dermatological conditions impairing NIRS measurement sites
• Restrictive lung disease, interstitial lung disease, or small-airway disease
• Participation in an exercise program within the last 12 months

Healthy Controls

• Age 40-70 years
• No acute or chronic disease
• Non-smoker
• BMI 18.5-24.9 kg/m²
• No musculoskeletal limitations

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Diagnostic
• Allocation: Non-Randomized
• Interventional Model: Parallel Assignment
• Masking: None (Open Label)

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: COPD	Other: Aerobic Exercise (Treadmill Walking); Participants perform treadmill walking for 15 minutes at 60% of the heart rate reserve (HRR), following a 2-minute warm-up period. Exercise intensity is calculated individually using the Karvonen formula. Continuous oxygenation monitoring is conducted via fNIRS (prefrontal cortex) and NIRS (vastus lateralis).; Other: Resistance Exercise (Upper and Lower Limb Strength Training); Participants perform resistance exercises for upper and lower limb major muscle groups using 60% of one-repetition maximum (1RM). Each exercise consists of 12 repetitions per set, repeated for 15 minutes with 10-second rest intervals between sets. Movements include shoulder flexion/abduction/extension, hip flexion/abduction/adduction/extension, knee extension, and squatting.; Other: Breathing Exercises; Participants perform controlled breathing exercises including diaphragmatic, chest, and lateral basal breathing techniques. Each pattern is executed in 10-repetition cycles, repeated for 15 minutes with 10-second rest intervals. All sessions begin with pursed-lip breathing instruction and are performed in a seated position.; Other: Cognitive Task (Stroop Task); A computerized color-word interference test (PsychoPy software) is administered before and after the exercise session to evaluate executive function and attention. Performance is analyzed in relation to concurrent fNIRS measurements from the prefrontal cortex.
Experimental: Healthy Individuals	Other: Aerobic Exercise (Treadmill Walking); Participants perform treadmill walking for 15 minutes at 60% of the heart rate reserve (HRR), following a 2-minute warm-up period. Exercise intensity is calculated individually using the Karvonen formula. Continuous oxygenation monitoring is conducted via fNIRS (prefrontal cortex) and NIRS (vastus lateralis).; Other: Resistance Exercise (Upper and Lower Limb Strength Training); Participants perform resistance exercises for upper and lower limb major muscle groups using 60% of one-repetition maximum (1RM). Each exercise consists of 12 repetitions per set, repeated for 15 minutes with 10-second rest intervals between sets. Movements include shoulder flexion/abduction/extension, hip flexion/abduction/adduction/extension, knee extension, and squatting.; Other: Breathing Exercises; Participants perform controlled breathing exercises including diaphragmatic, chest, and lateral basal breathing techniques. Each pattern is executed in 10-repetition cycles, repeated for 15 minutes with 10-second rest intervals. All sessions begin with pursed-lip breathing instruction and are performed in a seated position.; Other: Cognitive Task (Stroop Task); A computerized color-word interference test (PsychoPy software) is administered before and after the exercise session to evaluate executive function and attention. Performance is analyzed in relation to concurrent fNIRS measurements from the prefrontal cortex.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change in cerebral oxygenation during exercise	fNIRS device (Artinis Brite Lite, The Netherlands) with 8-channel prefrontal montage, sampling at 10 Hz. Data analyzed with MATLAB-based Homer3 and NIRS-KIT software.	Day 1

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change in peripheral muscle oxygenation	NIRS device (Moxy, Fortiori Design LLC, Minnesota, USA). Parameters analyzed include minimum, maximum, and mean SmO₂ and tHb.	Day 1
Cognitive performance (reaction time, accuracy in Stroop task)	Cognitive performance measured as reaction time (ms) and accuracy (%) during a computerized Stroop task performed before and after the exercise session. This reflects acute changes in executive function and attention related to cerebral oxygenation.	Pre-exercise (baseline) and immediately post-exercise (within 5 minutes after final exercise).
Six-Minute Walk Distance (6MWD)	Functional exercise capacity assessed using the standardized 6-minute walk test according to American Thoracic Society (ATS) guidelines. Distance covered is recorded in meters. Test repeated twice to minimize learning effect, and the better result is used for analysis.	Baseline
Perceived Dyspnea (Modified Borg Scale)	Participant-reported dyspnea level evaluated before and after each exercise modality using the Modified Borg Scale (0-10).	Day 1
Physical Activity Level (IPAQ-Short Form)	Self-reported physical activity level evaluated using the International Physical Activity Questionnaire - Short Form (IPAQ-SF). Results expressed in MET-min/week.	Baseline

Collaborators and Investigators

• Sponsor: Saglik Bilimleri Universitesi

Study record dates

Study Major Dates

• Study Start (Actual): April 30, 2025
• Primary Completion (Estimated): November 1, 2026
• Study Completion (Estimated): November 1, 2026

Study Registration Dates

• First Submitted: November 20, 2025
• First Submitted That Met QC Criteria: December 12, 2025
• First Posted (Actual): December 16, 2025

Study Record Updates

• Last Update Posted (Actual): April 15, 2026
• Last Update Submitted That Met QC Criteria: April 13, 2026
• Last Verified: April 1, 2026

More Information

Terms related to this study

• Keywords: COPD; Brain; Quadriceps femoris; FNIRS
• Additional Relevant MeSH Terms: Pathologic Processes; Chronic Disease; Disease Attributes; Respiratory Tract Diseases; Lung Diseases; Lung Diseases, Obstructive; Pathological Conditions, Signs and Symptoms; Pulmonary Disease, Chronic Obstructive; Motor Activity; Movement; Musculoskeletal Physiological Phenomena; Musculoskeletal and Neural Physiological Phenomena; Therapeutics; Mind-Body Therapies; Complementary Therapies; Exercise Movement Techniques; Physical Therapy Modalities; Behavioral Disciplines and Activities; Psychological Tests; Neuropsychological Tests; Exercise; Breathing Exercises; Stroop Test
• Other Study ID Numbers: fNIRS&Exercise

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No