Acute Musculoskeletal Responses to Blood Flow Restriction Training

NCT07848048 | Completed

• 2 other identifiers: UVAL-BFR-2025-012025-FIS-3834518
• Study Type: interventional
• Target: 66
• Locations: 1 country
• Sites: 1

Brief Summary

This randomized controlled trial investigated the acute musculoskeletal responses to isometric exercise with and without blood flow restriction in healthy, physically active young adults. Participants were randomly assigned to one of three groups: high-intensity isometric exercise (HI), low-intensity isometric exercise with blood flow restriction (LI-BFR), or low-intensity isometric exercise with sham blood flow restriction (LI-Sham). Ultrasound measurements of patellar tendon and vastus medialis muscle thickness were obtained before and immediately after the exercise intervention. Knee-extension maximal voluntary isometric contraction was also assessed. The study aimed to compare the acute changes in these outcomes among the three exercise conditions.

Conditions

Healthy Participants

Keywords

low-intensity resistance exercise; Rehabilitation; Vascular occlusion; Tendon morphology; Isometric contraction; Ultrasonography

Outcome Measures

Primary Outcomes (1)

• Change in Patellar Tendon Thickness

  Patellar tendon thickness was assessed by B-mode ultrasonography at 25%, 50%, and 75% of the tendon length, from the inferior pole of the patella to the tibial tuberosity.

  Baseline and immediately post-intervention

Secondary Outcomes (2)

• Change in Vastus Medialis Muscle Thickness

  Baseline and immediately post-intervention

• Change in Knee-Extension Maximal Voluntary Isometric Contraction (MVIC)

  Baseline and immediately post-intervention

Study Arms (3)

High-Intensity Isometric Exercise (HI)

EXPERIMENTAL

Participants performed five 30-second isometric knee-extension contractions at 70% of maximal voluntary isometric contraction (MVIC), with 60 seconds of rest between sets.

Behavioral: High-Intensity Isometric Exercise

Low-Intensity Isometric Exercise With Blood Flow Restriction (LI-BFR)

EXPERIMENTAL

Participants performed five 30-second isometric knee-extension contractions at 30% of MVIC with a pneumatic cuff inflated to 80% of the individual arterial occlusion pressure (AOP) during each contraction. The cuff was deflated during the 60-second rest periods between sets.

Behavioral: Low-Intensity Isometric Exercise With Blood Flow Restriction

Low-Intensity Isometric Exercise With Sham Blood Flow Restriction (LI-Sham)

EXPERIMENTAL

Participants performed five 30-second isometric knee-extension contractions at 30% of MVIC with a pneumatic cuff inflated to 20 mmHg during each contraction. The cuff was deflated during the 60-second rest periods between sets.

Behavioral: Low-Intensity Isometric Exercise With Sham Blood Flow Restriction

Interventions

Low-Intensity Isometric Exercise With Blood Flow Restriction BEHAVIORAL

Participants performed five 30-second isometric knee-extension contractions at 30% of MVIC with a pneumatic cuff inflated to 80% of the individual arterial occlusion pressure (AOP) during each contraction. The cuff was deflated during the 60-second rest periods between sets.

Low-Intensity Isometric Exercise With Blood Flow Restriction (LI-BFR)

Low-Intensity Isometric Exercise With Sham Blood Flow Restriction BEHAVIORAL

Participants performed five 30-second isometric knee-extension contractions at 30% of MVIC with a pneumatic cuff inflated to 20 mmHg during each contraction. The cuff was deflated during the 60-second rest periods between sets.

Low-Intensity Isometric Exercise With Sham Blood Flow Restriction (LI-Sham)

High-Intensity Isometric Exercise BEHAVIORAL

Participants performed five 30-second isometric knee-extension contractions at 70% of maximal voluntary isometric contraction (MVIC), with 60 seconds of rest between sets.

High-Intensity Isometric Exercise (HI)

Eligibility Criteria

• Age: 18 Years - 40 Years
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64)

You may qualify if:

• \- Healthy men and women aged 18-40 years.

You may not qualify if:

• Current musculoskeletal injury.
• Cardiovascular disease.
• Inability to complete the study protocol.
• Diagnosis of patellar tendinopathy within the previous 6 months.
• Contraindications to blood flow restriction, including pregnancy, thrombosis, excessive varicose veins, or a prosthesis in the region to be occluded.

Sponsors & Collaborators

• University of Valencia: lead

Study Sites (1)

University of Valencia

Valencia, Valencia, 46010, Spain

Location

Study Officials

• Yasser Alakhdar Mohmara

  University of Valencia

  PRINCIPAL INVESTIGATOR

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: DOUBLE
• Who Masked: PARTICIPANT, OUTCOMES ASSESSOR
• Purpose: BASIC SCIENCE
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Professor / Principal Investigator

Study Record Dates

• First Submitted: September 22, 2026
• First Posted: September 29, 2026
• Study Start: October 13, 2025
• Primary Completion: April 24, 2026
• Study Completion: April 24, 2026
• Last Updated: September 29, 2026

Record last verified: 2026-09

Data Sharing

• IPD Sharing: Will not share

Locations

ES (1)