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

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

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

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.

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