Nordic vs Blood Flow Restriction Nordic Exercise in Elite Female Pole Vaulters

July 10, 2026 updated by: Idil Esin Unlu, Toros University

Effects of Nordic Hamstring Exercise and Blood Flow Restriction-Assisted Nordic Hamstring Exercise on Hamstring Strength, Muscle Morphology and Functional Performance in Elite Adolescent Female Pole Vaulters: A Randomized Controlled Trial

The purpose of this randomized controlled trial is to compare the effects of Nordic Hamstring Exercise (NHE) and Blood Flow Restriction-assisted Nordic Hamstring Exercise (BFR-NHE) on hamstring muscle strength, muscle morphology, and functional performance in elite adolescent female pole vaulters. Thirty-six athletes aged 12-18 years will be randomly assigned to a Nordic Hamstring Exercise group, a Blood Flow Restriction-assisted Nordic Hamstring Exercise group, or a control group. Intervention groups will participate in supervised exercise training three times per week for eight weeks, while the control group will continue routine sports training. Outcomes will be assessed before and after the intervention period.

Study Overview

Status

Recruiting

Conditions

Intervention / Treatment

Detailed Description

Hamstring muscles play a crucial role in sprinting, acceleration, deceleration, and explosive athletic performance. Nordic Hamstring Exercise is widely recommended for increasing eccentric hamstring strength and reducing injury risk. However, evidence regarding the additional effects of blood flow restriction during Nordic Hamstring Exercise is limited, particularly in elite adolescent female athletes.

This randomized controlled trial aims to investigate whether adding blood flow restriction to Nordic Hamstring Exercise enhances adaptations in hamstring muscle strength, muscle morphology, and functional performance compared with conventional Nordic Hamstring Exercise and routine training alone.

Thirty-six elite adolescent female pole vaulters aged 12-18 years will be recruited from the Turkish Olympic Preparation Center. Participants will be allocated using block randomization into three groups:

Nordic Hamstring Exercise Group Blood Flow Restriction Nordic Hamstring Exercise Group Control Group Intervention groups will perform supervised exercise sessions three times weekly for eight weeks. The control group will continue regular training activities without additional hamstring-specific intervention.

Assessments will include hamstring muscle strength measured with a MicroFET2 handheld dynamometer, muscle morphology assessed using ultrasonography, and functional performance evaluated using a 30-meter sprint test.

Study Type

Interventional

Enrollment (Estimated)

36

Phase

  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Locations

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

  • Child
  • Adult

Accepts Healthy Volunteers

Yes

Description

Inclusion Criteria:

  • Female athletes aged between 12 and 18 years.
  • Elite pole vault athletes actively participating in organized training and competition.
  • Minimum of 1 year of regular pole vault training experience.
  • Participation in regular training at least 3 times per week.
  • Ability to participate in an 8-week exercise program.
  • Written informed assent from the athlete and written informed consent from a parent or legal guardian.

Exclusion Criteria:

  • Any lower extremity musculoskeletal injury within the previous 6 months.
  • Previous hamstring muscle surgery.
  • Current pain or injury limiting sports participation.
  • Neurological disorders affecting movement or balance.
  • Cardiovascular conditions contraindicating exercise training or blood flow restriction.
  • Any contraindication to blood flow restriction training.
  • Participation in another structured hamstring strengthening program during the study period.
  • Inability or unwillingness to comply with study procedures.

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

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

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: Nordic Hamstring Exercise
Participants will perform a supervised Nordic Hamstring Exercise program three times per week for 8 weeks in addition to their routine pole vault training.
Behavioral: Nordic Hamstring Exercise
Participants will perform a supervised Nordic Hamstring Exercise program three times per week for 8 weeks in addition to their routine pole vault training. The exercise program will be progressively increased according to participant tolerance and training progression.
Experimental: Blood Flow Restriction-Assisted Nordic Hamstring Exercise
Participants will perform Nordic Hamstring Exercise combined with blood flow restriction training three times per week for 8 weeks in addition to their routine pole vault training.
Behavioral: Blood Flow Restriction-Assisted Nordic Hamstring Exercise
articipants will perform a supervised Nordic Hamstring Exercise program combined with individualized blood flow restriction training three times per week for 8 weeks in addition to their routine pole vault training. Blood flow restriction will be applied using pneumatic cuffs at a predetermined percentage of arterial occlusion pressure.
No Intervention: Control
Participants will continue their routine sports training without additional hamstring-specific exercise intervention.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Hamstring Muscle Strength
Time Frame: Baseline and 8 weeks
Isometric hamstring muscle strength will be assessed bilaterally using a MicroFET2 handheld dynamometer. Three measurements will be recorded and the average value will be used for analysis.
Baseline and 8 weeks
Hamstring Muscle Thickness
Time Frame: Baseline and 8 weeks
Hamstring muscle thickness will be evaluated bilaterally using ultrasonography. Three measurements will be obtained and averaged.
Baseline and 8 weeks
Hamstring Cross-Sectional Area
Time Frame: Baseline and 8 weeks
Cross-sectional area of the hamstring muscle will be assessed bilaterally using ultrasonography.
Baseline and 8 weeks

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
30-Meter Sprint Performance
Time Frame: Baseline and 8 weeks
Sprint performance will be assessed using a 30-meter sprint test. The average of three trials will be used for analysis.
Baseline and 8 weeks

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Toros University

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

May 27, 2026

Primary Completion (Estimated)

March 1, 2027

Study Completion (Estimated)

April 1, 2027

Study Registration Dates

First Submitted

July 6, 2026

First Submitted That Met QC Criteria

July 10, 2026

First Posted (Actual)

July 15, 2026

Study Record Updates

Last Update Posted (Actual)

July 15, 2026

Last Update Submitted That Met QC Criteria

July 10, 2026

Last Verified

July 1, 2026

More Information

Terms related to this study

Keywords

Other Study ID Numbers

  • 25.05.2026-05/82

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

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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