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Effects of velocity loss during resistance training on athletic performance, strength gains and muscle adaptations
Author(s) -
ParejaBlanco F.,
RodríguezRosell D.,
SánchezMedina L.,
SanchisMoysi J.,
Dorado C.,
MoraCustodio R.,
YáñezGarcía J. M.,
MoralesAlamo D.,
PérezSuárez I.,
Calbet J. A. L.,
GonzálezBadillo J. J.
Publication year - 2017
Publication title -
scandinavian journal of medicine and science in sports
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.575
H-Index - 115
eISSN - 1600-0838
pISSN - 0905-7188
DOI - 10.1111/sms.12678
Subject(s) - squat , resistance training , sprint , medicine , vastus lateralis muscle , concentric , one repetition maximum , bench press , strength training , exercise physiology , leg press , muscle hypertrophy , physical medicine and rehabilitation , physical therapy , cardiology , mathematics , skeletal muscle , geometry
We compared the effects of two resistance training ( RT ) programs only differing in the repetition velocity loss allowed in each set: 20% ( VL 20) vs 40% ( VL 40) on muscle structural and functional adaptations. Twenty‐two young males were randomly assigned to a VL 20 ( n = 12) or VL 40 ( n = 10) group. Subjects followed an 8‐week velocity‐based RT program using the squat exercise while monitoring repetition velocity. Pre‐ and post‐training assessments included: magnetic resonance imaging, vastus lateralis biopsies for muscle cross‐sectional area ( CSA ) and fiber type analyses, one‐repetition maximum strength and full load‐velocity squat profile, countermovement jump ( CMJ ), and 20‐m sprint running. VL 20 resulted in similar squat strength gains than VL 40 and greater improvements in CMJ (9.5% vs 3.5%, P < 0.05), despite VL 20 performing 40% fewer repetitions. Although both groups increased mean fiber CSA and whole quadriceps muscle volume, VL 40 training elicited a greater hypertrophy of vastus lateralis and intermedius than VL 20. Training resulted in a reduction of myosin heavy chain IIX percentage in VL 40, whereas it was preserved in VL 20. In conclusion, the progressive accumulation of muscle fatigue as indicated by a more pronounced repetition velocity loss appears as an important variable in the configuration of the resistance exercise stimulus as it influences functional and structural neuromuscular adaptations.