Resistance Exercise Blood Flow Restriction (BFRCL)

Skeletal Muscle Endurance Responses to Various Relative Loads of Dynamic Resistance Exercise with and Without Peripheral Blood Flow Occlusion

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.

Study Overview

• Status: Completed
• Conditions: Skeletal Muscle Endurance
• Intervention / Treatment: Other: Resistance exercise

Detailed Description

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
• Enrollment (Actual): 29
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Canada
  • British Columbia
    • Vancouver, British Columbia, Canada, V6T 1Z3
      • Chan Gunn Pavilion

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult
• Accepts Healthy Volunteers: Yes

Description

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)

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Basic Science
• Allocation: Randomized
• Interventional Model: Factorial Assignment
• Masking: None (Open Label)

Number of Arms

12

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: 80% knee extension/80% barbell curl 1RM; The load will be set to 80% of 1RM for the knee extension and 80% 1RM for the barbell curl	Other: Resistance exercise; All arms will involve participants performing resistance exercise bouts of the described exercises. at the given loads, and with the stated flow condition
Experimental: 40% knee extension/70% barbell curl 1RM; The load will be set to 40% of 1RM for the knee extension and 70% 1RM for the barbell curl	Other: Resistance exercise; All arms will involve participants performing resistance exercise bouts of the described exercises. at the given loads, and with the stated flow condition
Experimental: 30% knee extension/60% barbell curl 1RM; The load will be set to 30% of 1RM for the knee extension and 60% 1RM for the barbell curl	Other: Resistance exercise; All arms will involve participants performing resistance exercise bouts of the described exercises. at the given loads, and with the stated flow condition
Experimental: 25% knee extension/55% barbell curl 1RM; The load will be set to 25% of 1RM for the knee extension and 55% 1RM for the barbell curl	Other: Resistance exercise; All arms will involve participants performing resistance exercise bouts of the described exercises. at the given loads, and with the stated flow condition
Experimental: 20% knee extension/50% barbell curl 1RM; The load will be set to 25% of 1RM for the knee extension and 50% 1RM for the barbell curl	Other: Resistance exercise; All arms will involve participants performing resistance exercise bouts of the described exercises. at the given loads, and with the stated flow condition
Experimental: 15% knee extension/45% barbell curl 1RM; The load will be set to 15% of 1RM for the knee extension and 45% 1RM for the barbell curl	Other: Resistance exercise; All arms will involve participants performing resistance exercise bouts of the described exercises. at the given loads, and with the stated flow condition
Experimental: 80% knee extension/80% barbell curl 1RM both with blood flow occlusion; The load will be set to 80% of 1RM for the knee extension and 80% 1RM for the barbell curl with both being under peripheral blood flow occlusion	Other: Resistance exercise; All arms will involve participants performing resistance exercise bouts of the described exercises. at the given loads, and with the stated flow condition
Experimental: 40% knee extension/60% barbell curl 1RM both with blood flow occlusion; The load will be set to 40% of 1RM for the knee extension and 60% 1RM for the barbell curl with both being under peripheral blood flow occlusion	Other: Resistance exercise; All arms will involve participants performing resistance exercise bouts of the described exercises. at the given loads, and with the stated flow condition
Experimental: 30% knee extension/60% barbell curl 1RM both with blood flow occlusion; The load will be set to 30% of 1RM for the knee extension and 60% 1RM for the barbell curl with both being under peripheral blood flow occlusion	Other: Resistance exercise; All arms will involve participants performing resistance exercise bouts of the described exercises. at the given loads, and with the stated flow condition
Experimental: 25% knee extension/55% barbell curl 1RM both with blood flow occlusion; The load will be set to 25% of 1RM for the knee extension and 55% 1RM for the barbell curl with both being under peripheral blood flow occlusion	Other: Resistance exercise; All arms will involve participants performing resistance exercise bouts of the described exercises. at the given loads, and with the stated flow condition
Experimental: 20% knee extension/50% barbell curl 1RM both with blood flow occlusion; The load will be set to 20% of 1RM for the knee extension and 50% 1RM for the barbell curl with both being under peripheral blood flow occlusion	Other: Resistance exercise; All arms will involve participants performing resistance exercise bouts of the described exercises. at the given loads, and with the stated flow condition
Experimental: 15% knee extension/45% barbell curl 1RM both with blood flow occlusion; The load will be set to 15% of 1RM for the knee extension and 45% 1RM for the barbell curl with both being under peripheral blood flow occlusion	Other: Resistance exercise; All arms will involve participants performing resistance exercise bouts of the described exercises. at the given loads, and with the stated flow condition

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Maximum knee extension repetitions	total repetitions completed for each load condition	From weeks two to three in the study

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Maximum barbell curl repetitions	total repetitions completed for each load condition	From weeks two to three in the study
Change in vastus lateralis oxygen saturation	The change in vastus lateralis oxygen saturation across each load condition	From weeks two to three in the study
Correlation of muscle fiber size/type/distribution to maximum knee extension repetitions at 20% 1RM		From weeks two to three in the study
Correlation of mitochondrial content to maximum knee extension repetitions at 20% 1RM		From weeks two to three in the study
Correlation of capillary density to maximum knee extension repetitions at 20% 1RM		From weeks two to three in the study
Comparison of muscle fiber size/type/distribution, mitochondrial function, mitochondrial density, capillary density, absolute muscle size ,and VO2 max between participants of different training statuses		Week 3
Correlation of absolute muscle size to maximum knee extension repetitions at 20% 1RM/barbell curl repetitions at 45% 1RM		Weeks 1, 2, and 3
Correlation of absolute muscle size to maximum knee extension repetitions at 20% 1RM/barbell curl repetitions at 45% 1RM		Week 1
Correlation of absolute muscle size to maximum knee extension repetitions at 20% 1RM/barbell curl repetitions at 45% 1RM		Week 2
Comparison of absolute muscle size between sexes		Week 3
Comparison of capillary density between sexes		Week 3
Comparison of mitochondrial density between sexes		Week 3
Comparison of muscle fiber distribution between sexes		Week 3
Comparison of muscle fiber size between sexes		Week 3
Comparison of muscle fiber type between sexes		Week 3
Comparison of mitochondrial function between sexes		Week 3
Comparison of VO2 max between sexes		Week 3
Correlation of VO2 max to maximum knee extension repetitions at 20% 1RM		Week 1
Correlation of VO2 max to maximum knee extension repetitions at 20% 1RM		Week 2
Correlation of VO2 max to maximum knee extension repetitions at 20% 1RM		Week 3

Collaborators and Investigators

• Sponsor: University of British Columbia

Study record dates

Study Major Dates

• Study Start (Actual): January 28, 2023
• Primary Completion (Actual): November 21, 2023
• Study Completion (Actual): November 21, 2023

Study Registration Dates

• First Submitted: June 9, 2023
• First Submitted That Met QC Criteria: December 4, 2024
• First Posted (Estimated): December 9, 2024

Study Record Updates

• Last Update Posted (Estimated): December 9, 2024
• Last Update Submitted That Met QC Criteria: December 4, 2024
• Last Verified: June 1, 2023

More Information

Terms related to this study

• Other Study ID Numbers: BFRCL

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO
• IPD Plan Description: A plan has not yet been made to make individual participant data available to other researchers

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No
• product manufactured in and exported from the U.S.: No