Acute Muscular and Vascular Responses to a Single Session of Exercise With BFR in COPD

N/ANot Yet RecruitingNCT07668921

University Hospital, Grenoble40 enrolled

Overview

Exercise training is a cornerstone of pulmonary rehabilitation (PR) in patients with chronic obstructive pulmonary disease (COPD). However, some patients derive limited benefits from conventional exercise programs. Previous studies suggest that the magnitude of exercise-induced muscle fatigue is associated with training effectiveness, with patients unable to develop significant muscle fatigue ("non-fatiguers") showing smaller improvements in functional capacity and quality of life. Blood flow restriction (BFR) exercise consists in performing physical exercise while applying external pressure to the proximal part of the exercising limb, thereby reducing oxygen delivery to the muscles and limiting metabolite clearance. This approach has been shown to induce significant muscular adaptations despite the use of low exercise intensities. Because exercise intensity in COPD patients is often constrained by ventilatory limitations, BFR training may enhance muscle adaptations while reducing respiratory stress, potentially improving the effectiveness of PR. The primary objective of this monocentric randomized crossover study is to compare lower-limb muscle fatigue induced by a single exercise session performed with BFR versus a standard exercise session in patients with COPD.

Two exercise modalities commonly used in pulmonary rehabilitation will be investigated independently in two sub-studies: (1) resistance training performed with BFR or without BFR, and (2) aerobic endurance training performed with BFR or without BFR.

Study Type

INTERVENTIONAL

Allocation

RANDOMIZED

Purpose

TREATMENT

Masking

NONE

Enrollment

Conditions

Interventions

Blood Flow RestrictionDEVICE

Sub-study 1 (RE-BFR): Resistance training consisting of 1 × 30 repetitions followed by 3 × 15 repetitions at 30% 1-RM, performed with thigh BFR to 50-60% of arterial occlusion pressure (AOP). Sub-study 2 (END-BFR): Low-intensity cycling exercise (\~30% peak aerobic power) performed with thigh BFR to 50-60% of AOP.

Standard exercise sessionDEVICE

Sub-study 1 (RE): Resistance exercise consisting of 4 × 10 repetitions at 60-70% 1-RM. Sub-study 2 (END): Conventional aerobic endurance cycling exercise performed at \~50% peak aerobic power.

Eligibility

Sex: ALLMin age: 45 Years

Medical Language ↔ Plain English

Inclusion Criteria: * Negative pregnancy test and use of an acceptable contraceptive method throughout the study duration for women of childbearing potential * Established COPD defined as obstructive ventilatory defect (FEV1/FVC \< 0.70 or below the 5th percentile) * Resting lung hyperinflation defined as functional residual capacity \> 2.5 z-scores according to the Global Lung Function Initiative (GLI) * Clinical stability of COPD for at least 3 months, with no recent exacerbation requiring treatment modification * Covered by a national health insurance system * Able and willing to provide written informed consent Non-inclusion Criteria: * Presence of a medical device incompatible with magnetic stimulation * Inability to perform an exercise test on a cycle ergometer * Any usual contraindication to exercise testing, including: * Recent myocardial infarction (3-5 days) * Unstable coronary insufficiency * Severe stenotic valvular disease * Uncontrolled arrhythmia with hemodynamic instability * Recent unexplained syncope * Uncontrolled heart failure * Uncontrolled arterial hypertension (systolic blood pressure ≥200 mmHg and/or diastolic blood pressure ≥110 mmHg at rest) * Acute thromboembolic disease and/or pulmonary edema * Conditions contraindicating the use of blood flow restriction (BFR), including: * Coagulation disorder * Peripheral neuropathy * Uncontrolled hypertension (\>160/100 mmHg) * Peripheral arterial disease * History of venous thrombosis * Intensive care unit stay within the last 3 months * Participation in another study during an exclusion period * Inability to be contacted in case of emergency * Individuals covered under Articles L1121-5 to L1121-8 of the French Public Health Code (protected populations, including pregnant or breastfeeding women, prisoners, minors, individuals under legal protection, psychiatric inpatients, etc.) * Staff members with a hierarchical relationship with the principal investigator

Outcomes

Primary Outcomes

Muscle fatigue

Muscle fatigue assessed by magnetic stimulation of the femoral nerve

Time frame: Assessed 15-minutes before, and 3, 30, 60-minutes after exercise

Secondary Outcomes

Flow Mediated Dilation (FMD)

Brachial artery FMD assessed by ultrasound

Time frame: 30-minutes pre-exercise, and 10 and 75-minutes post-exercise

Symptoms of dyspnea

Modified Borg scale: ranging from 0 (nothing at all) to 10 (maximal)

Time frame: Assessed at the end of each exercise set/bout (sub-study 1) or every 2 minutes throughout exercise (sub-study 2)

Leg discomfort

Modified Borg scale: ranging from 0 (nothing at all) to 10 (maximal)

Time frame: Assessed at the end of each exercise set/bout (sub-study 1) or every 2 minutes throughout exercise (sub-study 2)

Affective valence

Feeling scale: ranging from -5 (very bad) to 5 (very good)

Time frame: Assessed at the end of each exercise set/bout (sub-study 1) or every 2 minutes throughout exercise (sub-study 2)

Affective intensity

Felt Arousal Scale: ranging from 1 (low activation state) to 6 (high activation state)

Time frame: Assessed at the end of each exercise set/bout (sub-study 1) or every 2 minutes throughout exercise (sub-study 2)

Oxygen uptake

Using metabolic chart, in L/min

Time frame: Assessed at the end of each exercise set/bout (sub-study 1) or continuously throughout exercise (sub-study 2).

Carbon dioxide output

Using metabolic chart, in L/min

Time frame: Assessed at the end of each exercise set/bout (sub-study 1) or continuously throughout exercise (sub-study 2).

Minute ventilation

Using metabolic chart, in L/min

Time frame: Assessed at the end of each exercise set/bout (sub-study 1) or continuously throughout exercise (sub-study 2).

Breathing pattern

Tidal volume (in L) and respiratory rate (in breaths per minute), using metabolic chart

Time frame: Assessed at the end of each exercise set/bout (sub-study 1) or continuously throughout exercise (sub-study 2).

Heart rate

Using electrocardiogram, in beats/min

Time frame: Continuous monitoring throughout the exercise session.

Blood pressure

Using digital cuff system, in mmHg

Time frame: Continuous monitoring throughout the exercise session.

Cardiac output

Using impedance cardiography, in L/min

Time frame: Continuous monitoring throughout the exercise session.

Acute Muscular and Vascular Responses to a Single Session of Exercise With BFR in COPD

Overview

Conditions

Interventions

Eligibility

Locations (1)

Outcomes

Primary Outcomes

Secondary Outcomes

Central Contacts