NCT07237854

Effect of Training Intensity on Microvascular Function

Effect of Continuous Versus High-intensity Interval Aerobic Training on the Muscular Vascular Adaptation

• Status: Completed
• Phase: N/A
• Study type: Interventional
• Enrollment: 25 (actual)
• Sponsor: Université Libre de Bruxelles · Academic / Other
• Sex: All
• Age: 18 Years – 45 Years
• Healthy volunteers: Accepted

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.

Conditions

• Vascular Remodeling
• Sedentary Behavior
• Hemodynamic Rebound

Interventions

Type	Name	Description
PROCEDURE	Percutaneous muscle biopsies of the vastus lateralis (quadriceps)	Percutaneous muscle biopsies of the vastus lateralis (quadriceps) were performed under local anesthesia. Samples were collected at baseline and/or post-intervention to assess microvascular structure, fiber composition, and molecular adaptations to aerobic training.
OTHER	Measurement of the maximal oxygen uptake (VO2max)	Cardiopulmonary Exercise Testing (CPET) Maximal oxygen consumption (VO₂max) was assessed using an incremental stepwise protocol on a cycle ergometer. Participants performed the test at baseline and after the 8-week training intervention. Respiratory gas exchange was continuously measured using a COSMED K5 portable metabolic system, which provided breath-by-breath analysis of oxygen uptake (VO₂), carbon dioxide production (VCO₂), and ventilation parameters. The test was terminated upon volitional exhaustion or when predefined criteria for VO₂max plateau were met.
OTHER	Non-Invasive Cardiac Output Measurement (Innocor)	Maximal cardiac output was assessed at peak exercise intensity during cardiopulmonary exercise testing (CPET) using the Innocor device. This system employs the inert gas rebreathing technique, which involves the controlled inhalation of a gas mixture containing nitrous oxide (N₂O) and sulfur hexafluoride (SF₆). By analyzing the washout kinetics of these gases during rebreathing, the device estimates pulmonary blood flow, which is then used to calculate cardiac output non-invasively. Measurements were performed at the maximal workload reached during the incremental cycling test.

Timeline

• Start date: 2022-01-22
• Primary completion: 2024-08-15
• Completion: 2024-12-31
• First posted: 2025-11-20
• Last updated: 2025-11-20

Locations

1 site across 1 country: Belgium