Juan Sánchez-Valdepeñas, Pedro J Cornejo-Daza, José Páez-Maldonado, Luis Rodiles-Guerrero, Clara Cano-Castillo, Francisco Piqueras-Sanchiz, Juan José González-Badillo, Eduardo Sáez de Villarreal, Fernando Pareja-Blanco
{"title":"Acute Responses to Different Velocity-Loss Thresholds During Squat Training With and Without Blood-Flow Restriction.","authors":"Juan Sánchez-Valdepeñas, Pedro J Cornejo-Daza, José Páez-Maldonado, Luis Rodiles-Guerrero, Clara Cano-Castillo, Francisco Piqueras-Sanchiz, Juan José González-Badillo, Eduardo Sáez de Villarreal, Fernando Pareja-Blanco","doi":"10.1123/ijspp.2024-0236","DOIUrl":null,"url":null,"abstract":"<p><strong>Purpose: </strong>To compare the acute effects on mechanical, metabolic, neuromuscular, and muscle contractile responses to different velocity-loss (VL) thresholds (20% and 40%) under distinct blood-flow conditions (free [FF] vs restricted [BFR]) in full squat (SQ).</p><p><strong>Methods: </strong>Twenty strength-trained men performed 4 SQ protocols with 60% 1-repetition maximum that differed in the VL within the set and in the blood-flow condition (FF20: FF with 20% VL; FF40: FF with 40% VL; BFR20: BFR with 20% VL; and BFR40: BFR with 40% VL). The level of BFR was 50% of the arterial occlusion pressure. Before and after the SQ protocols, the following tests were performed: (1) tensiomyography, (2) blood lactate, (3) countermovement jump, (4) maximal voluntary isometric SQ contraction, and (5) performance with the load that elicited a 1 m·s-1 at baseline measurements in SQ.</p><p><strong>Results: </strong>No \"BFR × VL\" interactions were observed. BFR protocols resulted in fewer repetitions and lower increases in lactate concentration than FF protocols. The 40% VL protocols completed more repetitions but resulted in lower mechanical performance and electromyography median frequency during the exercise than the 20% VL protocols. At postexercise, the 40% VL protocols also experienced greater blood lactate concentrations, higher alterations in tensiomyography-derived variables, and accentuated impairments in SQ and countermovement-jump performances. The 20% VL protocols showed an increased electromyography median frequency at postexercise maximal voluntary isometric contraction.</p><p><strong>Conclusions: </strong>Despite BFR-accelerated fatigue development during exercise, a given VL magnitude induced similar impairments in the distinct performance indicators assessed, regardless of the blood-flow condition.</p>","PeriodicalId":14295,"journal":{"name":"International journal of sports physiology and performance","volume":" ","pages":"1-11"},"PeriodicalIF":3.5000,"publicationDate":"2024-12-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"International journal of sports physiology and performance","FirstCategoryId":"3","ListUrlMain":"https://doi.org/10.1123/ijspp.2024-0236","RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"PHYSIOLOGY","Score":null,"Total":0}
引用次数: 0
Abstract
Purpose: To compare the acute effects on mechanical, metabolic, neuromuscular, and muscle contractile responses to different velocity-loss (VL) thresholds (20% and 40%) under distinct blood-flow conditions (free [FF] vs restricted [BFR]) in full squat (SQ).
Methods: Twenty strength-trained men performed 4 SQ protocols with 60% 1-repetition maximum that differed in the VL within the set and in the blood-flow condition (FF20: FF with 20% VL; FF40: FF with 40% VL; BFR20: BFR with 20% VL; and BFR40: BFR with 40% VL). The level of BFR was 50% of the arterial occlusion pressure. Before and after the SQ protocols, the following tests were performed: (1) tensiomyography, (2) blood lactate, (3) countermovement jump, (4) maximal voluntary isometric SQ contraction, and (5) performance with the load that elicited a 1 m·s-1 at baseline measurements in SQ.
Results: No "BFR × VL" interactions were observed. BFR protocols resulted in fewer repetitions and lower increases in lactate concentration than FF protocols. The 40% VL protocols completed more repetitions but resulted in lower mechanical performance and electromyography median frequency during the exercise than the 20% VL protocols. At postexercise, the 40% VL protocols also experienced greater blood lactate concentrations, higher alterations in tensiomyography-derived variables, and accentuated impairments in SQ and countermovement-jump performances. The 20% VL protocols showed an increased electromyography median frequency at postexercise maximal voluntary isometric contraction.
Conclusions: Despite BFR-accelerated fatigue development during exercise, a given VL magnitude induced similar impairments in the distinct performance indicators assessed, regardless of the blood-flow condition.
期刊介绍:
The International Journal of Sports Physiology and Performance (IJSPP) focuses on sport physiology and performance and is dedicated to advancing the knowledge of sport and exercise physiologists, sport-performance researchers, and other sport scientists. The journal publishes authoritative peer-reviewed research in sport physiology and related disciplines, with an emphasis on work having direct practical applications in enhancing sport performance in sport physiology and related disciplines. IJSPP publishes 10 issues per year: January, February, March, April, May, July, August, September, October, and November.