Clinical trial NCT03055260: Low Intensity Blood Flow Restriction Training Study
Official title: Effect of Low Intensity Blood Flow Restriction Training on Lower Extremity Strength and Hypertrophy
Study type: INTERVENTIONAL
Overall status: COMPLETED
Phase: NA
Conditions: Muscle Mass
Lead sponsor: University of Minnesota
Sponsor class: OTHER
Collaborators: name: Fairview Health Services
First posted: 2017-02-16
Enrollment: 8
Sex: ALL
Minimum age (years): 18
Maximum age (years): 49
Standard ages: ADULT
Accepts healthy volunteers: yes
Allocation: RANDOMIZED
Intervention model: PARALLEL
Primary purpose: BASIC_SCIENCE

Brief summary: The particpant will complete baseline testing by measuring subjects' quadriceps muscle thickness (cm) via ultrasound technology, as well as have them complete a one repetition maximum (1RM) test on the leg press machine and an isometric knee extension using a dynamometer - strength measures will be calculated for both right and left legs. After baseline testing, subjects will complete 6 weeks of the testing protocol that will consist of leg press exercises at 30% of their 1RM. Subjects will be randomized to either wear a cuff that partially restricts blood flow to the limb (Study Group), or to wear a cuff that does not restrict blood flow (Control Group). Exercises will be completed 2x/week and will take approximately 10 total minutes (5 for warm up, 5 for testing protocol) per session. After 6 weeks, muscle thickness, leg press 1RM, and quadriceps extension strength will be re-tested and compared to the initial measurements.

Detailed description: Session 1 - baseline testing

* 5-minute warm-up; 1RM calculation for both right and left legs using a supine leg press machine; isometric quadriceps strength measurement using a dynamometer; muscle thickness measurements of both right and left quadriceps muscle using ultrasound technology.
* After day 1 testing; randomly allocate subjects to either control group or experimental group

Sessions 2-13 - 6 weeks of exercise protocol, 2x/per week

Both the experimental and control groups will complete the same protocol for the entirety of the study:

* 5- minute warm up
* Using a single-leg press exercise machine: Subjects complete the testing protocol with either partial blood flow restriction (cuff inflated to 100-250 mmhg depending on size of person) or no blood flow restriction (placebo inflation) on right limb.

  * Protocol: 30 repetitions - 15 repetitions - 15 repetitions - 15 repetitions with each set separated by \~30-90 seconds.
  * Right and left legs will be alternating, but only one leg will have the occlusion cuff

Session 14 - Re-test

- Re-check 1RM, isometric quad strength, as well as muscle thickness of quadriceps with ultrasound

Eligibility criteria: Inclusion Criteria:

* Age 18-49

Exclusion Criteria:

* Pregnant
* Hypertensive
* Recent back or lower extremity injury
* History of blood clotting
* Varicose veins
* Adults lacking the capacity to consent for themselves

Primary outcomes:
measure: One Repetition Maximum
timeFrame: 6 weeks
Secondary outcomes:
measure: Quadriceps Muscle Thickness
timeFrame: 6 weeks
Other outcomes:
Locations:
city: Minneapolis
country: United States
facility: Fairview Health Services
state: Minnesota
Study officials:
affiliation: Fairview Health Services
name: Jon Schoenecker, DPT
role: PRINCIPAL_INVESTIGATOR
References:
citation: Loenneke JP, Wilson JM, Marin PJ, Zourdos MC, Bemben MG. Low intensity blood flow restriction training: a meta-analysis. Eur J Appl Physiol. 2012 May;112(5):1849-59. doi: 10.1007/s00421-011-2167-x. Epub 2011 Sep 16.
citation: Slysz J, Stultz J, Burr JF. The efficacy of blood flow restricted exercise: A systematic review & meta-analysis. J Sci Med Sport. 2016 Aug;19(8):669-75. doi: 10.1016/j.jsams.2015.09.005. Epub 2015 Sep 28.