Abstract

Low-load blood flow restriction (LLBFR) training has been shown to elicit greater increases in muscle hypertrophy and strength compared to traditional low-load training, yet few studies have compared the effectiveness of different LLBFR protocols. To our knowledge, no previous study has compared the acute neuromuscular changes induced by two common LLBFR protocols: 30-15-15-15 repetitions (BFR-75) and four sets of repetitions performed to volitional failure (BFR-F). Therefore, the purpose of this study was to use surface electromyography (sEMG) to compare changes in muscle excitation and fatigue during BFR-75 and BFR-F protocols. Ten women (mean ± SD age = 22 ± 3.5 years) volunteered to participate in this investigation. Participants performed isokinetic, unilateral, concentric-eccentric, leg extension muscle actions at 30% maximal voluntary isometric contraction torque with BFR applied at 60% arterial occlusion pressure using a 12-centimeter-wide cuff. The sEMG amplitude and frequency values were measured from the rectus femoris muscle during the beginning and end of each set of exercise and analyzed using separate 2 [condition (BFR-75 and BFR-F)] x 8 [time (B1, E1, B2, E2, B3, E3, B4, E4)] repeated measures ANOVAs. For sEMG amplitude, there was no significant 2-way interaction (p = 0.486; ηₚ² = 0.118) or significant main effect for condition (p = 0.617; ηₚ² = 0.038), but there was a significant main effect for time (p < 0.001; ηₚ² = 0.520). SEMG amplitude increased across time during both protocols (B1 < E1, E2, B3, E3, B4, E4, p ≤ 0.001–0.049). For sEMG frequency, there was no significant 2-way interaction (p = 0.847; ηₚ² = 0.064) or significant main effect for condition (p = 0.825; ηₚ² = 0.007), but there was a significant main effect for time (p = 0.006; ηₚ² = 0.478). SEMG frequency decreased across time during both protocols (B1 > E1, B2, E2, B3, E3, B4, E4, p = 0.002–0.035). Thus, the implementation of the BFR-75 and BFR-F protocols elicited comparable neuromuscular responses that were consistent with fatiguing exercise, but investigators and clinicians may consider other factors such as participant/patient comfort, time, and rating of perceived exertion when determining which protocol to use.

Thesis Completion

2022

Semester

Spring

Thesis Chair/Advisor

Hill, Ethan

Degree

Bachelor of Science (B.S.)

College

College of Health Professions and Sciences

Department

School of Kinesiology and Physical Therapy

Degree Program

Kinesiology

Language

English

Access Status

Open Access

Release Date

3-15-2022

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Kinesiology Commons

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