Resistance Exercise Blood Flow Restriction

University of British Columbia29 enrolled

Overview

The number of repetitions able to be performed during resistance exercise is impacted by the load an individual is working against. Heavier loads lead to less repetitions being performed and lighter loads lead to more repetitions being performed. As the load gets progressively lighter, it is hypothesized that oxygen availability becomes an important factor for performance of maximum repetitions. Peripheral blood flow occlusion using exercise specific blood flow occlusion cuffs can allow for oxygen availability to be controlled by altering the amount of blood able to get to working muscles. To date, no study has examined the effect of varying exercise loads, from heavy to light, on maximum repetitions able to be performed with and without blood flow occlusion.

The study aims to assess the difference in maximum repetitions performed at varying percentages of participants maximum strength and the impact peripheral blood flow occlusion has on performance The study will take three weeks to complete with a total of six visits. The entire time commitment will be seven hours. During week 1 participants will visit the lab twice to perform baseline assessments of strength, endurance, muscle size and will also receive a resting thighs muscle biopsy. During weeks 2 and 3 participants will visit the lab twice per week to complete three out of twelve randomized exercise interventions per visit. The interventions are maximum repetitions at 80/40/30/25/20/15% of knee-extension one-repetition maximum as well as 90/70/60/55/50/45% of barbell curl one-repetition maximum; all of the listed conditions will be tested in a free-flow and blood flow occluded state (i.e., 12 total exercise interventions for the knee extension and 12 total exercise interventions for the barbell curl).

Study Type

INTERVENTIONAL

Allocation

RANDOMIZED

Purpose

BASIC_SCIENCE

Masking

NONE

Enrollment

Eligibility

Sex: ALLMin age: 19 YearsMax age: 30 YearsHealthy volunteers:

Medical Language ↔ Plain English

Inclusion Criteria: 1. Able to understand and communicate in English 2. 19-30 years of age 3. All "No" answers on the Canadian Society for Exercise Physiology Get Active questionnaire or doctors' approval to participate 4. Untrained participants: no structured resistance and/or endurance training over the past 12-months (i.e., \>2 hours per week of structured/periodized training) 5. Resistance trained participants: structured resistance training over the past 12-months (i.e., \>2 hours per week of structured/periodized resistance training) 6. Endurance trained participants: structured resistance training over the past 12-months (i.e., \>2 hours per week of structured/periodized endurance training) Exclusion Criteria: 1. BMI lower than 18 or greater than 30 2. Current use of cigarettes or other nicotine devices 3. Any major uncontrolled cardiovascular, muscular, metabolic, and/or neurological disorders 4. Any medical condition impacting the ability to participate in maximal exercise 5. Type one or type two diabetes 6. Diagnosis of cancer or undergoing cancer treatment in the past 12 months 7. Taking blood-thinning medication or the presence of a bleeding disorder 8. Drug therapy with any drugs that alter skeletal muscle metabolism (i.e., Metformin, Benzodiazepines) 9. Lowest calculated exercise testing load is less than the lightest weight able to be provided by the lab gymnasium equipment (i.e., 36 pounds for the knee extension, and/or 33 pounds for the barbell curl)