Effect of Limb Occlusion Pressure Attainment on Cardiovascular, Perceptual, and Performance Responses

Not Applicable

Not yet recruiting

• Conditions: Blood Flow Restriction (BFR) Training Effects; Arterial Stiffness, Blood Pressure; Muscle Morphology; Perceptions

• Registration Number: NCT06718582
• Lead Sponsor: Teri Herberger

Brief Summary

To test the effect of limb occlusion pressure attainment in the supine, seated, and standing position on exercise performance, vascular physiology, and muscle.

Detailed Description

The purpose of this study is to investigate the attainment of limb occlusion pressure (LOP)in the supine, seated, and standing positions on indices of arterial stiffness, muscle morphology, participant perception, and performance responses. Thirty adults aged 18-40 will undergo four treatment sessions (control (no BFR), supine LOP, seated LOP, and standing LOP) in a randomized order separated by one week. A familiarization session will also occur one week before starting the treatment period. Each subject will undergo a series of tests including anthropometry, ultrasonography of the carotid artery, applanation tonometry, ultrasonography of the vastus lateralis, blood pressure acquisition, body composition, and maximal strength assessments (1RM). All sessions will consist of four sets of dumbbell wall squats performed to failure with a 2-seconds concentric and 2-seconds eccentric cadence, at 20% of their 1RM using 60% of the LOP with 1-minute rest intervals. In the supine LOP session, the BFR cuffs will be pressurized to 60% of the supine LOP. In the seated LOP session, the BFR cuffs will be pressurized to 60% of the seated LOP. And, in the standing LOP session, the BFR cuffs will be pressurized to 60% of the standing LOP. Assessments will be performed immediately before and after the exercise bout during each treatment session. Two-way ANOVAs will be used to examine the main effects of treatment and treatment-order interaction on pulse wave velocity, muscle cross-sectional area, perceptual responses, and exercise performance.

Study Timeline

• Status Verified: 2024-11
• Study First Submitted: 2024-12-02
• Study First Submitted QC: 2024-12-02
• Last Update Submitted: 2024-12-02
• Study First Posted: 2024-12-05
• Last Update Posted: 2024-12-05
• Study Start: 2025-02-01
• Primary Completion: 2025-11-20
• Study Completion: 2025-12-20

Recruitment & Eligibility

• Status: NOT_YET_RECRUITING
• Sex: All
• Target Recruitment: 30

Inclusion Criteria

• Physically active (> 1,000 MET/min/wk) for at least six months. Weight stable for previous 6 months (+/-2.5 kg) Female subjects only- reported regular menstrual cycles for the last 2 years

Exclusion Criteria

1. BP>140/90 mmHg
2. BMI>40 kg/m2
3. Diabetes
4. Familial hypercholesterolemia
5. Past or current history of CHD, stroke or major CVD events. Respiratory diseases (not including asthma), endocrine or metabolic, neurological, or hematological disorders that would compromise the study or the health of the subject.
6. Women must not be pregnant, plan to become pregnant during the study, or be nursing
7. Active renal or liver disease
8. All medications and supplements that influence dependent variables*
9. Recent surgery < 2 months
10. Alcohol abuse
11. Sleep apnea
12. Claustrophobia

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: CROSSOVER

Primary Outcome Measures

Name	Time	Method
Arterial Stiffness	From enrollment to the end of treatment at 4 weeks	Non-invasive pulse tonometers (Complior Analytic Tonometer, Alam Medical, Vincennes, France) will be used to simultaneously obtain arterial pressure waveforms at the carotid, brachial, radial and femoral arteries throughout ten cardiac cycles. Surface distance between the two recording sites will be measured to the nearest 0.5 cm. Subsequently, this process is repeated to measure arterial pressure waveforms at the carotid and radial arteries. Pulse wave velocity for the carotid-femoral (aortic PWV) and carotid-radial (brachial PWV) recordings will be determined by normalizing the waveform foot-to-foot time delay to the distance between recording sites (i.e., PWV = D (cm)/Δt (sec)). The participant will remain supine exactly as they were positioned during the tonometry acquisition sequence. An enlarged caliper will be used to measure the distance between the carotid and radial tonometer, and the distance between the carotid and femoral tonometer.

Secondary Outcome Measures

Name	Time	Method
Muscle Morphology	From enrollment to the end of treatment at 4 weeks	Participants' muscle cross-sectional area (mCSA) and echo intensity (EI) of the vastus lateralis (VL) muscle will be assessed using a brightness mode (B-mode) of the ultrasound imaging system (Terason t3300, MA, USA) and a multi-frequency linear-array probe (Model 15L4 Smart Mark 4-15 MHz, 50-mm field of view). All ultrasonic scans will be conducted on the participants' right arm to measure the mCSA and EI of the VL. Each participant will be instructed to lay in a supine position with their shoulder abducted at 90 degree and elbow flexed at 90 degrees. The VL measurements will be obtained from their right leg at 50% of the distance between the greater tubercle and lateral epicondyle. Locations of measurements will be marked with indelible ink to ensure scans will be taken at the same area for all scans. During every scan, water soluble gel will be applied on the skin and ultrasound probe to maximize acoustic coupling and reduce near-field artifacts.