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Effects of resistance exercise combined with essential amino acid supplementation and energy deficit on markers of skeletal muscle atrophy and regeneration during bed rest and active recovery
Author(s) -
Brooks Naomi E.,
Cadena Samuel M.,
Vannier Edouard,
Cloutier Gregory,
Carambula Silvia,
Myburgh Kathryn H.,
Roubenoff Ronenn,
CastanedaSceppa Carmen
Publication year - 2010
Publication title -
muscle and nerve
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.025
H-Index - 145
eISSN - 1097-4598
pISSN - 0148-639X
DOI - 10.1002/mus.21780
Subject(s) - myod , myogenin , medicine , myostatin , endocrinology , muscle atrophy , skeletal muscle , spaceflight , atrophy , sarcopenia , amyotrophy , biology , myogenesis , engineering , aerospace engineering
Spaceflight and bed rest (BR) lead to muscle atrophy. This study assessed the effect of essential amino acid (EAA) supplementation and resistance training with decreased energy intake on molecular changes in skeletal muscle after 28‐day BR and 14‐day recovery. Thirty‐one men (31–55 years) subjected to an 8 ± 6% energy deficit were randomized to receive EAA without resistance training (AA, n = 7), or EAA 3 h after (RT, n = 12) or 5 min before (AART, n = 12) resistance training. During BR, myostatin transcript levels increased twofold in the AA group. During recovery, insulin‐like growth factor‐1 (IGF‐1) mRNA increased in all groups, whereas Pax7, MyoD, myogenin, and MRF4 transcripts increased in AA only (all P < 0.05). MAFbx transcripts decreased twofold with AA and RT. Satellite cells did not change during BR or recovery. This suggests that EAA alone is the least protective countermeasure to muscle loss, and several molecular mechanisms are proposed by which exercise attenuates muscle atrophy during BR with energy deficit. Muscle Nerve, 2010