Clinical trial NCT04938947: Resistance Training and Blood Flow Restriction
Official title: Effect of Resistance Training With Blood Flow Restriction on Motor Unit Hypertrophy in the Vastus Lateralis
Study type: INTERVENTIONAL
Overall status: COMPLETED
Phase: NA
Conditions: Blood Flow Restriction and Low-Intensity Resistance Training
Lead sponsor: University of Kansas
Sponsor class: OTHER
First posted: 2021-06-25
Enrollment: 31
Sex: ALL
Minimum age (years): 18
Maximum age (years): 30
Standard ages: ADULT
Accepts healthy volunteers: yes
Allocation: RANDOMIZED
Intervention model: PARALLEL
Primary purpose: BASIC_SCIENCE

Brief summary: The primary purposes of the proposed study is 1) To examine the changes of muscle fiber cross-sectional areas in the leg extensor muscles (vastus lateralis) pre- to post- 6 weeks of high-intensity resistance training and low-intensity resistance training with blood flow restriction and 2) To examine changes in motor unit size (a non-invasive measure of muscle fiber size) in the leg extensor muscles (vastus lateralis) pre- to post- 6 weeks of high-intensity resistance training and low-intensity resistance training with blood flow restriction.

Detailed description: Specific Aims and Hypotheses:

Specific Aim 1: To examine the changes of type I and II (different types of muscle fibers) muscle fiber cross-sectional areas in the leg extensor muscles (vastus lateralis) pre- to post- 6 weeks of high-intensity resistance training and low-intensity resistance training with blood flow restriction. Hypothesis 1: Type I and II fiber cross-sectional area will increase following low-intensity resistance training with blood flow restriction, however, only cross-sectional area of type II fibers will increase post high-intensity resistance training.

Specific Aim 2: To examine changes in the size of the motor units that are active during low and high intensity contractions in the leg extensor muscles (vastus lateralis) pre- to post- 6 weeks of high-intensity resistance training and low-intensity resistance training with blood flow restriction. Hypothesis 2: The motor units that are active during low and high intensity contractions will increase in size from low-intensity resistance training with blood flow restriction, but only the motor units that are active during high intensity contractions will increase in size from high-intensity resistance training.

Specific Aim 3: To examine changes in whole muscle cross-sectional area as measured via ultrasound pre- to post- 6 weeks of high-intensity resistance training and low-intensity resistance training with blood flow restriction. Hypothesis 3: Whole muscle cross-sectional area will increase to similar degrees from both high-intensity resistance training and low-intensity resistance training with blood flow restriction.

Eligibility criteria: Inclusion Criteria:

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Exclusion Criteria:

* Participants must not have participated in resistance training more than 5 times in the 6 months preceding the study.
* Participants must be healthy and free of any cardiovascular, metabolic or musculoskeletal conditions that may affect the results of the investigation.
* Participants must not have a history of severe hip, knee and/or ankle injuries, or any other pathological conditions that impair their motor control.
* Participants must not have any pre-existing cardiovascular conditions that involve blood flow/blood clotting.
* Participants who are currently taking blood thinners or any medications regulating blood pressures or heart rate will not be eligible to participate in the study.
* Female participants who are pregnant at the start of or who are planning to become pregnant during the resistance training intervention will not be eligible to participate in the study.

Primary outcomes:
measure: Determine changes in muscle fiber cross-sectional area
timeFrame: July 2021-May 2022
measure: Determine changes in motor unit size
timeFrame: July 2021- May 2022
Secondary outcomes:
Other outcomes:
Locations:
city: Lawrence
country: United States
facility: Robinson Center
state: Kansas
Study officials:
References: