Brooks NE, Cadena SM, Cloutier G, Vega-López S, Roubenoff R, Castaneda-Sceppa C. Influence of exercise on the metabolic profile caused by 28 days of bed rest with energy deficit and amino acid supplementation in healthy men.
Int J Med Sci 2014;
11:1248-57. [PMID:
25317071 PMCID:
PMC4196126 DOI:
10.7150/ijms.9694]
[Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/20/2014] [Accepted: 08/27/2014] [Indexed: 01/16/2023] Open
Abstract
OBJECTIVE
Muscle loss and metabolic changes occur with disuse [i.e. bed rest (BR)]. We hypothesized that BR would lead to a metabolically unhealthy profile defined by: increased circulating tumor necrosis factor (TNF)-α, decreased circulating insulin-like-growth-factor (IGF)-1, decreased HDL-cholesterol, and decreased muscle density (MD; measured by mid-thigh computerized tomography).
METHODS
We investigated the metabolic profile after 28 days of BR with 8 ± 6% energy deficit in male individuals (30-55 years) randomized to resistance exercise with amino acid supplementation (RT, n=24) or amino acid supplementation alone (EAA, n=7). Upper and lower body exercises were performed in the horizontal position. Blood samples were taken at baseline, after 28 days of BR and 14 days of recovery.
RESULTS
We found a shift toward a metabolically unfavourable profile after BR [compared to baseline (BLN)] in both groups as shown by decreased HDL-cholesterol levels (EAA: BLN: 39 ± 4 vs. BR: 32 ± 2 mg/dL, RT: BLN: 39 ± 1 vs. BR: 32 ± 1 mg/dL; p<0.001) and Low MD (EAA: BLN: 27 ± 4 vs. BR: 22 ± 3 cm(2), RT: BLN: 28 ± 2 vs. BR: 23 ± 2 cm(2); p<0.001). A healthier metabolic profile was maintained with exercise, including NormalMD (EAA: BLN: 124 ± 6 vs. BR: 110 ± 5 cm(2), RT: BLN: 132 ± 3 vs. BR: 131 ± 4 cm(2); p<0.001, time-by-group); although, exercise did not completely alleviate the unfavourable metabolic changes seen with BR. Interestingly, both groups had increased plasma IGF-1 levels (EAA: BLN:168 ± 22 vs. BR 213 ± 20 ng/mL, RT: BLN:180 ± 10 vs. BR: 219 ± 13 ng/mL; p<0.001) and neither group showed TNFα changes (p>0.05).
CONCLUSIONS
We conclude that RT can be incorporated to potentially offset the metabolic complications of BR.
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