The Impact of Blood Flow Restriction (BFR) on Exercise and Hemodynamic Responses
Overview
- Phase
- Not Applicable
- Intervention
- Not specified
- Conditions
- Exercise Training
- Sponsor
- University of Texas at Austin
- Enrollment
- 20
- Locations
- 1
- Primary Endpoint
- Flow-mediated Dilation
- Status
- Terminated
- Last Updated
- 5 years ago
Overview
Brief Summary
The impact of blood flow restriction (BFR) on exercise and hemodynamic responses will be studied. The use of BFR will be studied during yoga and low-intensity aerobic exercise in healthy subjects with no history of chronic illness ranging from 18-40 years of age. This study will evaluate several conditions related to cardiovascular physiology in order to determine the safety and efficacy of this type of exercise training. First, the effects of two distinct types of BFR cuffs (BStrong and Hokanson) will be studied during low-intensity aerobic exercise on vascular function. Second, the effect of yoga will be studied with and without the use of BStrong bands on vascular function. Outcome measures include acute effects on endothelial function i.e. flow-mediated dilation, arterial stiffness, beat-by-beat blood pressure, heart rate, RPE (rate of perceived exertion), and blood lactate. For this intervention, the BFR cuffs will be used during exercise to evaluate its safety and efficacy. Since BFR is becoming a widely popular method of exercise, it is important to study its safety and hemodynamic effects.
Detailed Description
Participants will be tested a total of 5 times; twice for the yoga portion and thrice for the aerobic exercise (walking) portion. Outcome measures will be consistent across the five visits and will take approximately 2.5 hours to complete. The order of the five separate sessions will be randomized such that the participant cannot expect which condition they will be performing.
Investigators
Hirofumi Tanaka
Professor
University of Texas at Austin
Eligibility Criteria
Inclusion Criteria
- •Healthy adults
Exclusion Criteria
- •Pregnancy
- •A recent illness, recent surgery, or any medical intervention
- •history of diabetes, heart disease, or other cardiovascular problems
Outcomes
Primary Outcomes
Flow-mediated Dilation
Time Frame: Before (baseline) and after the exercise interventions
After 20 minutes of supine rest, endothelial function was measured via flow-mediated dilation (FMD) technique by measuring the brachial artery's diameter increase following a brief period of occlusion using an automated diagnostic ultrasound system. A blood pressure cuff was placed on the forearm with the proximal edge of the cuff above with the participant's antecubital fossa. Two cross-sectional images of the artery were acquired utilizing the automated ultrasound probe proximal to the antecubital fossa. Following baseline metrics, the cuff was inflated to 50 mmHg above resting systolic blood pressure for 5 minutes to occlude blood flow. After 5 minutes of occlusion, the cuff was deflated, and both brachial artery diameter and blood flow velocity were measured simultaneously and continuously for two-minutes immediately post occlusion. FMD was calculated as a percent increase in brachial artery diameter at the post-blood flow occlusion compared with the pre-blood flow occlusion.
Systolic Blood Pressure
Time Frame: Measurements were taken at Baseline (before Experimental Arm Participation) and immediately after Experimental Arm Participation.
Arterial blood pressure was measured using the automatic oscillometric methods.