Abstract
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.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
