Concurrent exercise on a gravity-independent device during simulated microgravity.
Author(s)
Cotter, Joshua AYu, Alvin
Haddad, Fadia
Kreitenberg, Arthur
Baker, Michael J
Tesch, Per A
Baldwin, Kenneth M
Caiozzo, Vincent J
Adams, Gregory R
Keywords
AgedAtrophy
Exercise: physiology
Female
Humans
Male
Middle Aged
Muscle Fatigue: physiology
Muscle Strength: physiology
Muscle
Skeletal: growth & development
pathology
physiology
Oxygen Consumption
Physical Education and Training: methods
RNA
Messenger: metabolism
Resistance Training
Weightlessness Simulation: instrumentation
Young Adult
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https://escholarship.org/uc/item/9pg280gpAbstract
The objective of this study is to examine the effect of a high-intensity concurrent training program using a single gravity-independent device on maintaining skeletal muscle function and aerobic capacity during short-term unilateral lower limb suspension (ULLS).Nineteen subjects (10 males and 9 females; 21.0 ± 2.5 yr, 65.4 ± 12.2 kg) were separated into two groups: 1) 10-d ULLS only (n = 9) and 2) 10-d ULLS plus aerobic and resistance training (ULLS + EX, n = 10). Exercise was performed on a single gravity-independent Multi-Mode Exercise Device (M-MED) with alternating days of high-intensity interval aerobic training and maximal exertion resistance training.Aerobic capacity increased by 7% in ULLS + EX (P < 0.05). Knee extensor and ankle plantar flexor three-repetition maximum increased in the ULLS + EX group (P < 0.05), but this change was only different from ULLS in the plantar flexors (P < 0.05). Peak torque levels decreased with ULLS but were increased for the knee extensors and attenuated for the ankle plantar flexors with ULLS + EX (P < 0.05). A shift toward type IIx myosin heavy-chain mRNA occurred with ULLS and was reversed with ULLS + EX in the vastus lateralis (P < 0.05) but not the soleus. Myostatin and atrogin increased with ULLS in both the vastus lateralis and soleus, but this change was mitigated with ULLS + EX only in the vastus lateralis (P = 0.0551 for myostatin, P < 0.05 for atrogin). Citrate synthase was decreased in the soleus during ULLS but was increased with ULLS + EX (P < 0.05).These results indicate that an M-MED class countermeasure device appears to be effective at mitigating the deconditioning effects of microgravity simulated during a modified ULLS protocol.Date
2015-05-01Type
ArticleIdentifier
oai:escholarship.org/ark:/13030/qt9pg280gpqt9pg280gp
https://escholarship.org/uc/item/9pg280gp