title: The acute response of practical occlusion in the knee extensors.
abstract: Training at low intensities with moderate vascular occlusion results in increased muscle hypertrophy, strength, and endurance. Elastic knee wraps, applied to the proximal portion of the target muscle, might elicit a stimulus similar to the KAATSU Master Apparatus. The purpose of this study was to test the hypothesis that intermittently occluding the leg extensors with elastic knee wraps would increase whole-blood lactate (WBL) over control (CON). Twelve healthy men and women participated in this study (age 21.2 ± 0.35 years, height 168.9 ± 2.60 cm, and body mass 71.2 ± 4.16 kg). One repetition maximum (1RM) testing for the leg extensors was performed on a leg extension machine for the first trial, followed by occlusion (OCC) and CON trials. Four sets of leg extension exercise (30-15-15-15) were completed with 150-second rest between sets at 30% 1RM. Whole-blood lactate, heart rate (HR), and ratings of perceived exertion (RPEs) were measured after every set of exercise and 3 minutes postexercise. Data were analyzed using repeated-measures analysis of variance with statistical significance set at p ≤ 0.05. Whole-blood lactate increased in response to exercise (p = 0.01) but was not different between groups (OCC 6.28 ± 0.66 vs. CON 5.35 ± 0.36 mmol·L, p = 0.051). Heart rate (OCC 128.86 ± 4.37 vs. CON 119.72 ± 4.10 b·min⁻¹) was higher with OCC from sets 2-4 (p ≤ 0.03), with no difference 3 minutes postexercise (p = 0.29). Rating of perceived exertion was higher with OCC after every set (OCC 15.10 ± 0.31 vs. CON 12.16 ± 0.50, p = 0.01). In conclusion, no differences exist for WBL between groups, although there was a trend for higher levels with OCC. The current protocol for practical occlusion did not significantly increase metabolic stress more than normal low-intensity exercise. This study does not support the use of knee wraps as a mode of blood-flow restriction.
authors.affiliation: Department of Health, Human Performance, and Recreation, Southeast Missouri State University, Cape Girardeau, Missouri, USA. jploenneke1s@semo.edu
authors.forename: Jeremy P
authors.initials: JP
authors.lastname: Loenneke
authors.forename: Monica L
authors.initials: ML
authors.lastname: Kearney
authors.forename: Austin D
authors.initials: AD
authors.lastname: Thrower
authors.forename: Sean
authors.initials: S
authors.lastname: Collins
authors.forename: Thomas J
authors.initials: TJ
authors.lastname: Pujol
mesh_terms: D015444:Exercise; D005260:Female; D006339:Heart Rate / Q000502:physiology; D006801:Humans; D007717:Knee / Q000098:blood supply* / Q000502:physiology*; D019344:Lactic Acid / Q000097:blood; D008297:Male; D018482:Muscle, Skeletal / Q000098:blood supply* / Q000502:physiology*; D005082:Physical Exertion / Q000502:physiology; D012039:Regional Blood Flow / Q000502:physiology*; D053828:Stockings, Compression; D055815:Young Adult
chemical_list: D019344:Lactic Acid