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.

Acute Cardiovascular and Hemodynamic Responses to Low Intensity Eccentric Resistance Exercise with Blood Flow Restriction

“…This may be related to the amount of exercise and muscle groups involved (one vs four), the form of contraction (eccentric vs concentric and eccentric) and time under tension were higher in the study performed by Neto et al (31). However, the reduction in oxygen saturation observed in the study by Neto et al (31) may have altered the supply of intramuscular oxygen, providing a more acidic ambient and an anabolic environment (28), a fact that could justify a higher RPE (extension and flexion of knees) in the protocol LI + BFR when compared to HI. In the present study there was no reduction in SpO 2 probably because eccentric contraction was performed in only one exercise movement and one muscle group (ECC knee extension of quadriceps muscle).…”

“…Rate of perceived exertion (RPE) assessed with the Borg, 6 - 20 scale (27, 28). RPE was assessed after each set of the exercise sessions.…”

Exercise and Blood Flow Restriction

“…Therefore, prescriptive exercise variables for clinical populations are not yet definable, but in healthy populations, BFR exercise may provide an alternative means of obtaining a hypertrophic effect in a relatively short time period. Application of external pressure to the proximal portion of the lower extremity (i.e., inguinal crease) or upper extremity (i.e., distal portion of deltoid) can be obtained via pressurized cuff or elastic knee wraps (53). It should be emphasized that the strength and hypertrophic adaptations may take place at muscles that are proximal or distal to the occlusion site (4).…”

Effects of cuff width on arterial occlusion: implications for blood flow restricted exercise

“…A variety of devices have been used to restrict blood flow during exercise, including elastic knee wraps (Loenneke et al 2010a, 2011a, b, d), elastic belts with a pneumatic bag inside (Fahs et al 2011; Rossow et al 2011), nylon pneumatic cuffs (Cook et al 2007; Manini et al 2011), or a traditional nylon blood pressure cuff (Laurentino et al 2008; Teramoto and Golding 2006). In addition, a range of restrictive cuff pressures have been used for restricting blood flow, generally ranging from approximately 1.3 times greater than systolic blood pressure (SBP; ~160 mmHg) to over 200 mmHg.…”