Effect of Training Intensity on Microvascular Function

Not Applicable

Completed

• Conditions: Vascular Remodeling; Sedentary Behavior; Hemodynamic Rebound

• Registration Number: NCT07237854
• Lead Sponsor: Université Libre de Bruxelles

Brief Summary

The aim of this trial is to investigate the effect of aerobic training intensity on muscle vascular function: continuous versus interval.

Detailed Description

This trial will compare the hemodynamic effects of aerobic training on muscle microvascular function between participants randomly assigned to one of two groups: a continuous training group and an high-intensity interval training group.

All data concerning the primary and secondary outcomes will be obtained at the start and repeated at the end of 8 weeks aerobic training.

Study Timeline

• Study Start: 2022-01-22
• Study First Submitted: 2022-09-26
• Primary Completion: 2024-08-15
• Study Completion: 2024-12-31
• Status Verified: 2025-10
• Study First Submitted QC: 2025-11-14
• Last Update Submitted: 2025-11-14
• Study First Posted: 2025-11-20
• Last Update Posted: 2025-11-20

Recruitment & Eligibility

• Status: COMPLETED
• Sex: All
• Target Recruitment: 25

Inclusion Criteria

• Healthy female or male between 18 and 45 years
• Be sedentary
• Able to cycle
• Able to provide written informed consent

Exclusion Criteria

• Have a pathology that may impact vascular function as :

  • cardiac pathology
  • pneumological pathology
  • metabolic pathology

• Smoke

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: PARALLEL

Primary Outcome Measures

Name	Time	Method
Percutaneous muscle biopsies of the vastus lateralis	At baseline and after completion of the 8-week intervention	Muscle tissue samples obtained from the vastus lateralis were processed using optical clearing and immunohistochemical staining techniques to visualize the microvascular network. Confocal microscopy was employed to acquire high-resolution three-dimensional images of arterioles, capillaries, and venules. Quantitative assessments included: 1. Internal diameter measurements, based on endothelial cell boundaries (intima layer); 2. External diameter measurements, based on smooth muscle cells and pericytes (media layer); 3. Capillary density, determined by counting the number of capillaries per sample volume

Secondary Outcome Measures

Name	Time	Method
Cardiopulmonary Exercise Testing (CPET)	At baseline and after completion of the 8-week intervention	VO₂max was determined using a graded, incremental exercise test performed on a cycle ergometer until volitional exhaustion. Throughout the test, respiratory gases were continuously measured using a metabolic cart (e.g., COSMED K5), which provided breath-by-breath analysis.; The following parameters were recorded : 1. VO₂ (oxygen uptake) in mL/min; 2. VCO₂ (carbon dioxide production) in mL/min; 3. Minute ventilation (VE) in L/min
Maximal Cardiac Output Measurement Using Inert Gas Rebreathing (Innocor)	At baseline and after completion of the 8-week intervention	Innocor is a medical device that estimates cardiac output using the inert gas rebreathing technique, a validated non-invasive method. During the procedure, the participant inhales a gas mixture containing nitrous oxide (N₂O) and sulfur hexafluoride (SF₆) through a closed circuit. These inert gases are absorbed and eliminated at rates proportional to pulmonary blood flow. By analyzing the washout kinetics of these gases during a brief rebreathing period, Innocor calculates pulmonary blood flow, which is then used to estimate cardiac output. This measurement is typically performed at rest or at peak exercise intensity, such as during the final stage of a cardiopulmonary exercise test (CPET).; The system provides real-time data on: 1. Cardiac output (L/min); 2. Stroke volume (ml/min); 3. Heart rate (bpm); 4. Pulmonary blood flow (L/min)

Trial Locations

Locations (1)

Université Libre de Bruxelles, Faculté des Sciences de la motricité, Laboratoire de kinésithérapie; 🇧🇪 Brussels, Anderlecht, Belgium