Acute Responses to High-Intensity Back Squats with Bilateral Blood Flow Restriction

• Published in: International journal of environmental research and public health 2023-02, Vol.20 (4), p.3555
• Main Authors: Hornikel, Bjoern, Saffold, Keith S, Esco, Michael R, Mota, Jacob A, Fedewa, Michael V, Wind, Stefanie A, Adams, Tiffany L, Winchester, Lee J
• Format: Article
• Language: English
• Subjects: Acute effects; Analysis; Angiogenesis; Biomarkers; Blood flow; Body fat; Computer peripherals industry; Electromyography; Ethylenediaminetetraacetic acid; Exercise; Fatigue; Female; Growth factors; Humans; Hypoxia; Interleukin 6; Interleukins; Kinases; Laboratories; Lactates; Lactic acid; Male; Metabolism; Metabolites; Muscle contraction; Muscle, Skeletal - physiology; Muscles; Muscular fatigue; Myoglobin; Myoglobins; Occlusion; Pain; Pain perception; Physical fitness; Protein synthesis; Proteins; Regional Blood Flow - physiology; Resistance factors; Resistance Training; Strength training; Vascular endothelial growth factor; Vascular Endothelial Growth Factor A; Vitamin E
• ISSN: 1660-4601; 1661-7827; 1660-4601
• DOI: 10.3390/ijerph20043555

This study examined the acute effects of high-intensity resistance exercise with blood flow restriction (BFR) on performance and fatigue, metabolic stress, and markers of inflammation (interleukin-6 (IL-6)), muscle damage (myoglobin), angiogenesis (vascular endothelial growth factor (VEGF)). Thirteen resistance-trained participants (four female, 24.8 ± 4.7 years) performed four sets of barbell back-squats (75% 1RM) to failure under two conditions: blood flow restriction (BFR, bilateral 80% occlusion pressure) and control (CTRL). Completed repetitions and pre-post-exercise changes in maximal voluntary isometric contractions, countermovement jump, barbell mean propulsive velocity, and surface electromyography were recorded. Pre-post blood lactate (BLa) and venous blood samples for analysis of IL-6, myoglobin, and VEGF were collected. Ratings of perceived exertion (RPE) and pain were recorded for each set. Fewer repetitions were performed during BFR (25.5 ± 9.6 reps) compared to CTRL (43.4 ± 14.2 reps, < 0.001), with greater repetitions performed during sets 1, 2, and 4 ( < 0.05) in CTRL. Although RPE between conditions was similar across all sets ( > 0.05), pain was greater in BFR across all sets ( < 0.05). Post-exercise fatigue was comparable between conditions. BLa was significantly greater in CTRL compared to BFR at two minutes ( = 0.001) but not four minutes post-exercise ( = 0.063). IL-6 was significantly elevated following BFR ( = 0.011). Comparable increases in myoglobin ( > 0.05) and no changes in VEGF were observed ( > 0.05). BFR increases the rate of muscular fatigue during high-intensity resistance exercise and acutely enhances IL-6 response, with significantly less total work performed, but increases pain perception, limiting implementation.